13 files changed, 384 insertions, 335 deletions
diff --git a/arch/alpha/include/asm/floppy.h b/arch/alpha/include/asm/floppy.h
index 942924756cf2..8dfdb3aa1d96 100644
--- a/arch/alpha/include/asm/floppy.h
+++ b/arch/alpha/include/asm/floppy.h
@@ -11,8 +11,8 @@
 #define __ASM_ALPHA_FLOPPY_H
 
 
-#define fd_inb(port)			inb_p(port)
-#define fd_outb(value,port)		outb_p(value,port)
+#define fd_inb(base, reg)		inb_p((base) + (reg))
+#define fd_outb(value, base, reg)	outb_p(value, (base) + (reg))
 
 #define fd_enable_dma()         enable_dma(FLOPPY_DMA)
 #define fd_disable_dma()        disable_dma(FLOPPY_DMA)
diff --git a/arch/arm/include/asm/floppy.h b/arch/arm/include/asm/floppy.h
index 79fa327238e8..e1cb04ed5008 100644
--- a/arch/arm/include/asm/floppy.h
+++ b/arch/arm/include/asm/floppy.h
@@ -9,20 +9,20 @@
 #ifndef __ASM_ARM_FLOPPY_H
 #define __ASM_ARM_FLOPPY_H
 
-#define fd_outb(val,port)						\
+#define fd_outb(val, base, reg)						\
 	do {								\
 		int new_val = (val);					\
-		if (((port) & 7) == FD_DOR) {				\
+		if ((reg) == FD_DOR) {					\
 			if (new_val & 0xf0)				\
 				new_val = (new_val & 0x0c) |		\
 					  floppy_selects[new_val & 3];	\
 			else						\
 				new_val &= 0x0c;			\
 		}							\
-		outb(new_val, (port));					\
+		outb(new_val, (base) + (reg));				\
 	} while(0)
 
-#define fd_inb(port)		inb((port))
+#define fd_inb(base, reg)	inb((base) + (reg))
 #define fd_request_irq()	request_irq(IRQ_FLOPPYDISK,floppy_interrupt,\
 					    0,"floppy",NULL)
 #define fd_free_irq()		free_irq(IRQ_FLOPPYDISK,NULL)
diff --git a/arch/m68k/include/asm/floppy.h b/arch/m68k/include/asm/floppy.h
index c3b9ad6732fc..a4d0fea47c6b 100644
--- a/arch/m68k/include/asm/floppy.h
+++ b/arch/m68k/include/asm/floppy.h
@@ -63,21 +63,21 @@ static __inline__ void release_dma_lock(unsigned long flags)
 }
 
 
-static __inline__ unsigned char fd_inb(int port)
+static __inline__ unsigned char fd_inb(int base, int reg)
 {
 	if(MACH_IS_Q40)
-		return inb_p(port);
+		return inb_p(base + reg);
 	else if(MACH_IS_SUN3X)
-		return sun3x_82072_fd_inb(port);
+		return sun3x_82072_fd_inb(base + reg);
 	return 0;
 }
 
-static __inline__ void fd_outb(unsigned char value, int port)
+static __inline__ void fd_outb(unsigned char value, int base, int reg)
 {
 	if(MACH_IS_Q40)
-		outb_p(value, port);
+		outb_p(value, base + reg);
 	else if(MACH_IS_SUN3X)
-		sun3x_82072_fd_outb(value, port);
+		sun3x_82072_fd_outb(value, base + reg);
 }
 
 
@@ -211,26 +211,27 @@ asmlinkage irqreturn_t floppy_hardint(int irq, void *dev_id)
 		st=1;
 		for(lcount=virtual_dma_count, lptr=virtual_dma_addr;
 		    lcount; lcount--, lptr++) {
-			st=inb(virtual_dma_port+4) & 0xa0 ;
-			if(st != 0xa0)
+			st = inb(virtual_dma_port + FD_STATUS);
+			st &= STATUS_DMA | STATUS_READY;
+			if (st != (STATUS_DMA | STATUS_READY))
 				break;
 			if(virtual_dma_mode)
-				outb_p(*lptr, virtual_dma_port+5);
+				outb_p(*lptr, virtual_dma_port + FD_DATA);
 			else
-				*lptr = inb_p(virtual_dma_port+5);
+				*lptr = inb_p(virtual_dma_port + FD_DATA);
 		}
 
 		virtual_dma_count = lcount;
 		virtual_dma_addr = lptr;
-		st = inb(virtual_dma_port+4);
+		st = inb(virtual_dma_port + FD_STATUS);
 	}
 
 #ifdef TRACE_FLPY_INT
 	calls++;
 #endif
-	if(st == 0x20)
+	if (st == STATUS_DMA)
 		return IRQ_HANDLED;
-	if(!(st & 0x20)) {
+	if (!(st & STATUS_DMA)) {
 		virtual_dma_residue += virtual_dma_count;
 		virtual_dma_count=0;
 #ifdef TRACE_FLPY_INT
diff --git a/arch/mips/include/asm/mach-generic/floppy.h b/arch/mips/include/asm/mach-generic/floppy.h
index 9ec2f6a5200b..e3f446d54827 100644
--- a/arch/mips/include/asm/mach-generic/floppy.h
+++ b/arch/mips/include/asm/mach-generic/floppy.h
@@ -26,14 +26,14 @@
 /*
  * How to access the FDC's registers.
  */
-static inline unsigned char fd_inb(unsigned int port)
+static inline unsigned char fd_inb(unsigned int base, unsigned int reg)
 {
-	return inb_p(port);
+	return inb_p(base + reg);
 }
 
-static inline void fd_outb(unsigned char value, unsigned int port)
+static inline void fd_outb(unsigned char value, unsigned int base, unsigned int reg)
 {
-	outb_p(value, port);
+	outb_p(value, base + reg);
 }
 
 /*
diff --git a/arch/mips/include/asm/mach-jazz/floppy.h b/arch/mips/include/asm/mach-jazz/floppy.h
index 4b86c88a03b7..095000c290e5 100644
--- a/arch/mips/include/asm/mach-jazz/floppy.h
+++ b/arch/mips/include/asm/mach-jazz/floppy.h
@@ -17,19 +17,19 @@
 #include <asm/jazzdma.h>
 #include <asm/pgtable.h>
 
-static inline unsigned char fd_inb(unsigned int port)
+static inline unsigned char fd_inb(unsigned int base, unsigned int reg)
 {
 	unsigned char c;
 
-	c = *(volatile unsigned char *) port;
+	c = *(volatile unsigned char *) (base + reg);
 	udelay(1);
 
 	return c;
 }
 
-static inline void fd_outb(unsigned char value, unsigned int port)
+static inline void fd_outb(unsigned char value, unsigned int base, unsigned int reg)
 {
-	*(volatile unsigned char *) port = value;
+	*(volatile unsigned char *) (base + reg) = value;
 }
 
 /*
diff --git a/arch/parisc/include/asm/floppy.h b/arch/parisc/include/asm/floppy.h
index 09b6f4c1687e..762cfe7778c0 100644
--- a/arch/parisc/include/asm/floppy.h
+++ b/arch/parisc/include/asm/floppy.h
@@ -29,8 +29,8 @@
 #define CSW fd_routine[can_use_virtual_dma & 1]
 
 
-#define fd_inb(port)			readb(port)
-#define fd_outb(value, port)		writeb(value, port)
+#define fd_inb(base, reg)		readb((base) + (reg))
+#define fd_outb(value, base, reg)	writeb(value, (base) + (reg))
 
 #define fd_request_dma()        CSW._request_dma(FLOPPY_DMA,"floppy")
 #define fd_free_dma()           CSW._free_dma(FLOPPY_DMA)
@@ -75,27 +75,28 @@ static void floppy_hardint(int irq, void *dev_id, struct pt_regs * regs)
 		register char *lptr = virtual_dma_addr;
 
 		for (lcount = virtual_dma_count; lcount; lcount--) {
-			st = fd_inb(virtual_dma_port+4) & 0xa0 ;
-			if (st != 0xa0) 
+			st = fd_inb(virtual_dma_port, FD_STATUS);
+			st &= STATUS_DMA | STATUS_READY;
+			if (st != (STATUS_DMA | STATUS_READY))
 				break;
 			if (virtual_dma_mode) {
-				fd_outb(*lptr, virtual_dma_port+5);
+				fd_outb(*lptr, virtual_dma_port, FD_DATA);
 			} else {
-				*lptr = fd_inb(virtual_dma_port+5);
+				*lptr = fd_inb(virtual_dma_port, FD_DATA);
 			}
 			lptr++;
 		}
 		virtual_dma_count = lcount;
 		virtual_dma_addr = lptr;
-		st = fd_inb(virtual_dma_port+4);
+		st = fd_inb(virtual_dma_port, FD_STATUS);
 	}
 
 #ifdef TRACE_FLPY_INT
 	calls++;
 #endif
-	if (st == 0x20)
+	if (st == STATUS_DMA)
 		return;
-	if (!(st & 0x20)) {
+	if (!(st & STATUS_DMA)) {
 		virtual_dma_residue += virtual_dma_count;
 		virtual_dma_count = 0;
 #ifdef TRACE_FLPY_INT
diff --git a/arch/powerpc/include/asm/floppy.h b/arch/powerpc/include/asm/floppy.h
index 167c44b58848..7af9a68fd949 100644
--- a/arch/powerpc/include/asm/floppy.h
+++ b/arch/powerpc/include/asm/floppy.h
@@ -13,8 +13,8 @@
 
 #include <asm/machdep.h>
 
-#define fd_inb(port)		inb_p(port)
-#define fd_outb(value,port)	outb_p(value,port)
+#define fd_inb(base, reg)		inb_p((base) + (reg))
+#define fd_outb(value, base, reg)	outb_p(value, (base) + (reg))
 
 #define fd_enable_dma()         enable_dma(FLOPPY_DMA)
 #define fd_disable_dma()	 fd_ops->_disable_dma(FLOPPY_DMA)
@@ -61,21 +61,22 @@ static irqreturn_t floppy_hardint(int irq, void *dev_id)
 	st = 1;
 	for (lcount=virtual_dma_count, lptr=virtual_dma_addr;
 	     lcount; lcount--, lptr++) {
-		st=inb(virtual_dma_port+4) & 0xa0 ;
-		if (st != 0xa0)
+		st = inb(virtual_dma_port + FD_STATUS);
+		st &= STATUS_DMA | STATUS_READY;
+		if (st != (STATUS_DMA | STATUS_READY))
 			break;
 		if (virtual_dma_mode)
-			outb_p(*lptr, virtual_dma_port+5);
+			outb_p(*lptr, virtual_dma_port + FD_DATA);
 		else
-			*lptr = inb_p(virtual_dma_port+5);
+			*lptr = inb_p(virtual_dma_port + FD_DATA);
 	}
 	virtual_dma_count = lcount;
 	virtual_dma_addr = lptr;
-	st = inb(virtual_dma_port+4);
+	st = inb(virtual_dma_port + FD_STATUS);
 
-	if (st == 0x20)
+	if (st == STATUS_DMA)
 		return IRQ_HANDLED;
-	if (!(st & 0x20)) {
+	if (!(st & STATUS_DMA)) {
 		virtual_dma_residue += virtual_dma_count;
 		virtual_dma_count=0;
 		doing_vdma = 0;
diff --git a/arch/sparc/include/asm/floppy_32.h b/arch/sparc/include/asm/floppy_32.h
index b519acf4383d..946dbcbf3a83 100644
--- a/arch/sparc/include/asm/floppy_32.h
+++ b/arch/sparc/include/asm/floppy_32.h
@@ -59,8 +59,8 @@ struct sun_floppy_ops {
 
 static struct sun_floppy_ops sun_fdops;
 
-#define fd_inb(port)              sun_fdops.fd_inb(port)
-#define fd_outb(value,port)       sun_fdops.fd_outb(value,port)
+#define fd_inb(base, reg)         sun_fdops.fd_inb(reg)
+#define fd_outb(value, base, reg) sun_fdops.fd_outb(value, reg)
 #define fd_enable_dma()           sun_fd_enable_dma()
 #define fd_disable_dma()          sun_fd_disable_dma()
 #define fd_request_dma()          (0) /* nothing... */
@@ -114,15 +114,15 @@ static unsigned char sun_read_dir(void)
 static unsigned char sun_82072_fd_inb(int port)
 {
 	udelay(5);
-	switch(port & 7) {
+	switch (port) {
 	default:
 		printk("floppy: Asked to read unknown port %d\n", port);
 		panic("floppy: Port bolixed.");
-	case 4: /* FD_STATUS */
+	case FD_STATUS:
 		return sun_fdc->status_82072 & ~STATUS_DMA;
-	case 5: /* FD_DATA */
+	case FD_DATA:
 		return sun_fdc->data_82072;
-	case 7: /* FD_DIR */
+	case FD_DIR:
 		return sun_read_dir();
 	}
 	panic("sun_82072_fd_inb: How did I get here?");
@@ -131,20 +131,20 @@ static unsigned char sun_82072_fd_inb(int port)
 static void sun_82072_fd_outb(unsigned char value, int port)
 {
 	udelay(5);
-	switch(port & 7) {
+	switch (port) {
 	default:
 		printk("floppy: Asked to write to unknown port %d\n", port);
 		panic("floppy: Port bolixed.");
-	case 2: /* FD_DOR */
+	case FD_DOR:
 		sun_set_dor(value, 0);
 		break;
-	case 5: /* FD_DATA */
+	case FD_DATA:
 		sun_fdc->data_82072 = value;
 		break;
-	case 7: /* FD_DCR */
+	case FD_DCR:
 		sun_fdc->dcr_82072 = value;
 		break;
-	case 4: /* FD_STATUS */
+	case FD_DSR:
 		sun_fdc->status_82072 = value;
 		break;
 	}
@@ -154,23 +154,23 @@ static void sun_82072_fd_outb(unsigned char value, int port)
 static unsigned char sun_82077_fd_inb(int port)
 {
 	udelay(5);
-	switch(port & 7) {
+	switch (port) {
 	default:
 		printk("floppy: Asked to read unknown port %d\n", port);
 		panic("floppy: Port bolixed.");
-	case 0: /* FD_STATUS_0 */
+	case FD_SRA:
 		return sun_fdc->status1_82077;
-	case 1: /* FD_STATUS_1 */
+	case FD_SRB:
 		return sun_fdc->status2_82077;
-	case 2: /* FD_DOR */
+	case FD_DOR:
 		return sun_fdc->dor_82077;
-	case 3: /* FD_TDR */
+	case FD_TDR:
 		return sun_fdc->tapectl_82077;
-	case 4: /* FD_STATUS */
+	case FD_STATUS:
 		return sun_fdc->status_82077 & ~STATUS_DMA;
-	case 5: /* FD_DATA */
+	case FD_DATA:
 		return sun_fdc->data_82077;
-	case 7: /* FD_DIR */
+	case FD_DIR:
 		return sun_read_dir();
 	}
 	panic("sun_82077_fd_inb: How did I get here?");
@@ -179,23 +179,23 @@ static unsigned char sun_82077_fd_inb(int port)
 static void sun_82077_fd_outb(unsigned char value, int port)
 {
 	udelay(5);
-	switch(port & 7) {
+	switch (port) {
 	default:
 		printk("floppy: Asked to write to unknown port %d\n", port);
 		panic("floppy: Port bolixed.");
-	case 2: /* FD_DOR */
+	case FD_DOR:
 		sun_set_dor(value, 1);
 		break;
-	case 5: /* FD_DATA */
+	case FD_DATA:
 		sun_fdc->data_82077 = value;
 		break;
-	case 7: /* FD_DCR */
+	case FD_DCR:
 		sun_fdc->dcr_82077 = value;
 		break;
-	case 4: /* FD_STATUS */
+	case FD_DSR:
 		sun_fdc->status_82077 = value;
 		break;
-	case 3: /* FD_TDR */
+	case FD_TDR:
 		sun_fdc->tapectl_82077 = value;
 		break;
 	}
diff --git a/arch/sparc/include/asm/floppy_64.h b/arch/sparc/include/asm/floppy_64.h
index 3729fc35ba83..070c8c1f5c8f 100644
--- a/arch/sparc/include/asm/floppy_64.h
+++ b/arch/sparc/include/asm/floppy_64.h
@@ -47,8 +47,9 @@ unsigned long fdc_status;
 static struct platform_device *floppy_op = NULL;
 
 struct sun_floppy_ops {
-	unsigned char	(*fd_inb) (unsigned long port);
-	void		(*fd_outb) (unsigned char value, unsigned long port);
+	unsigned char	(*fd_inb) (unsigned long port, unsigned int reg);
+	void		(*fd_outb) (unsigned char value, unsigned long base,
+				    unsigned int reg);
 	void		(*fd_enable_dma) (void);
 	void		(*fd_disable_dma) (void);
 	void		(*fd_set_dma_mode) (int);
@@ -62,8 +63,8 @@ struct sun_floppy_ops {
 
 static struct sun_floppy_ops sun_fdops;
 
-#define fd_inb(port)              sun_fdops.fd_inb(port)
-#define fd_outb(value,port)       sun_fdops.fd_outb(value,port)
+#define fd_inb(base, reg)         sun_fdops.fd_inb(base, reg)
+#define fd_outb(value, base, reg) sun_fdops.fd_outb(value, base, reg)
 #define fd_enable_dma()           sun_fdops.fd_enable_dma()
 #define fd_disable_dma()          sun_fdops.fd_disable_dma()
 #define fd_request_dma()          (0) /* nothing... */
@@ -97,42 +98,43 @@ static int sun_floppy_types[2] = { 0, 0 };
 /* No 64k boundary crossing problems on the Sparc. */
 #define CROSS_64KB(a,s) (0)
 
-static unsigned char sun_82077_fd_inb(unsigned long port)
+static unsigned char sun_82077_fd_inb(unsigned long base, unsigned int reg)
 {
 	udelay(5);
-	switch(port & 7) {
+	switch (reg) {
 	default:
-		printk("floppy: Asked to read unknown port %lx\n", port);
+		printk("floppy: Asked to read unknown port %x\n", reg);
 		panic("floppy: Port bolixed.");
-	case 4: /* FD_STATUS */
+	case FD_STATUS:
 		return sbus_readb(&sun_fdc->status_82077) & ~STATUS_DMA;
-	case 5: /* FD_DATA */
+	case FD_DATA:
 		return sbus_readb(&sun_fdc->data_82077);
-	case 7: /* FD_DIR */
+	case FD_DIR:
 		/* XXX: Is DCL on 0x80 in sun4m? */
 		return sbus_readb(&sun_fdc->dir_82077);
 	}
 	panic("sun_82072_fd_inb: How did I get here?");
 }
 
-static void sun_82077_fd_outb(unsigned char value, unsigned long port)
+static void sun_82077_fd_outb(unsigned char value, unsigned long base,
+			      unsigned int reg)
 {
 	udelay(5);
-	switch(port & 7) {
+	switch (reg) {
 	default:
-		printk("floppy: Asked to write to unknown port %lx\n", port);
+		printk("floppy: Asked to write to unknown port %x\n", reg);
 		panic("floppy: Port bolixed.");
-	case 2: /* FD_DOR */
+	case FD_DOR:
 		/* Happily, the 82077 has a real DOR register. */
 		sbus_writeb(value, &sun_fdc->dor_82077);
 		break;
-	case 5: /* FD_DATA */
+	case FD_DATA:
 		sbus_writeb(value, &sun_fdc->data_82077);
 		break;
-	case 7: /* FD_DCR */
+	case FD_DCR:
 		sbus_writeb(value, &sun_fdc->dcr_82077);
 		break;
-	case 4: /* FD_STATUS */
+	case FD_DSR:
 		sbus_writeb(value, &sun_fdc->status_82077);
 		break;
 	}
@@ -298,19 +300,21 @@ static struct sun_pci_dma_op sun_pci_dma_pending = { -1U, 0, 0, NULL};
 
 irqreturn_t floppy_interrupt(int irq, void *dev_id);
 
-static unsigned char sun_pci_fd_inb(unsigned long port)
+static unsigned char sun_pci_fd_inb(unsigned long base, unsigned int reg)
 {
 	udelay(5);
-	return inb(port);
+	return inb(base + reg);
 }
 
-static void sun_pci_fd_outb(unsigned char val, unsigned long port)
+static void sun_pci_fd_outb(unsigned char val, unsigned long base,
+			    unsigned int reg)
 {
 	udelay(5);
-	outb(val, port);
+	outb(val, base + reg);
 }
 
-static void sun_pci_fd_broken_outb(unsigned char val, unsigned long port)
+static void sun_pci_fd_broken_outb(unsigned char val, unsigned long base,
+				   unsigned int reg)
 {
 	udelay(5);
 	/*
@@ -320,16 +324,17 @@ static void sun_pci_fd_broken_outb(unsigned char val, unsigned long port)
 	 *      this does not hurt correct hardware like the AXmp.
 	 *      (Eddie, Sep 12 1998).
 	 */
-	if (port == ((unsigned long)sun_fdc) + 2) {
+	if (reg == FD_DOR) {
 		if (((val & 0x03) == sun_pci_broken_drive) && (val & 0x20)) {
 			val |= 0x10;
 		}
 	}
-	outb(val, port);
+	outb(val, base + reg);
 }
 
 #ifdef PCI_FDC_SWAP_DRIVES
-static void sun_pci_fd_lde_broken_outb(unsigned char val, unsigned long port)
+static void sun_pci_fd_lde_broken_outb(unsigned char val, unsigned long base,
+				       unsigned int reg)
 {
 	udelay(5);
 	/*
@@ -339,13 +344,13 @@ static void sun_pci_fd_lde_broken_outb(unsigned char val, unsigned long port)
 	 *      this does not hurt correct hardware like the AXmp.
 	 *      (Eddie, Sep 12 1998).
 	 */
-	if (port == ((unsigned long)sun_fdc) + 2) {
+	if (reg == FD_DOR) {
 		if (((val & 0x03) == sun_pci_broken_drive) && (val & 0x10)) {
 			val &= ~(0x03);
 			val |= 0x21;
 		}
 	}
-	outb(val, port);
+	outb(val, base + reg);
 }
 #endif /* PCI_FDC_SWAP_DRIVES */
 
diff --git a/arch/x86/include/asm/floppy.h b/arch/x86/include/asm/floppy.h
index 7ec59edde154..d43717b423cb 100644
--- a/arch/x86/include/asm/floppy.h
+++ b/arch/x86/include/asm/floppy.h
@@ -31,8 +31,8 @@
 #define CSW fd_routine[can_use_virtual_dma & 1]
 
 
-#define fd_inb(port)		inb_p(port)
-#define fd_outb(value, port)	outb_p(value, port)
+#define fd_inb(base, reg)		inb_p((base) + (reg))
+#define fd_outb(value, base, reg)	outb_p(value, (base) + (reg))
 
 #define fd_request_dma()	CSW._request_dma(FLOPPY_DMA, "floppy")
 #define fd_free_dma()		CSW._free_dma(FLOPPY_DMA)
@@ -77,25 +77,26 @@ static irqreturn_t floppy_hardint(int irq, void *dev_id)
 		st = 1;
 		for (lcount = virtual_dma_count, lptr = virtual_dma_addr;
 		     lcount; lcount--, lptr++) {
-			st = inb(virtual_dma_port + 4) & 0xa0;
-			if (st != 0xa0)
+			st = inb(virtual_dma_port + FD_STATUS);
+			st &= STATUS_DMA | STATUS_READY;
+			if (st != (STATUS_DMA | STATUS_READY))
 				break;
 			if (virtual_dma_mode)
-				outb_p(*lptr, virtual_dma_port + 5);
+				outb_p(*lptr, virtual_dma_port + FD_DATA);
 			else
-				*lptr = inb_p(virtual_dma_port + 5);
+				*lptr = inb_p(virtual_dma_port + FD_DATA);
 		}
 		virtual_dma_count = lcount;
 		virtual_dma_addr = lptr;
-		st = inb(virtual_dma_port + 4);
+		st = inb(virtual_dma_port + FD_STATUS);
 	}
 
 #ifdef TRACE_FLPY_INT
 	calls++;
 #endif
-	if (st == 0x20)
+	if (st == STATUS_DMA)
 		return IRQ_HANDLED;
-	if (!(st & 0x20)) {
+	if (!(st & STATUS_DMA)) {
 		virtual_dma_residue += virtual_dma_count;
 		virtual_dma_count = 0;
 #ifdef TRACE_FLPY_INT
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index c3daa64cb52c..064c1acb9f00 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -337,8 +337,7 @@ static bool initialized;
 /*
  * globals used by 'result()'
  */
-#define MAX_REPLIES 16
-static unsigned char reply_buffer[MAX_REPLIES];
+static unsigned char reply_buffer[FD_RAW_REPLY_SIZE];
 static int inr;		/* size of reply buffer, when called from interrupt */
 #define ST0		0
 #define ST1		1
@@ -595,12 +594,12 @@ static unsigned char in_sector_offset;	/* offset within physical sector,
 
 static inline unsigned char fdc_inb(int fdc, int reg)
 {
-	return fd_inb(fdc_state[fdc].address + reg);
+	return fd_inb(fdc_state[fdc].address, reg);
 }
 
 static inline void fdc_outb(unsigned char value, int fdc, int reg)
 {
-	fd_outb(value, fdc_state[fdc].address + reg);
+	fd_outb(value, fdc_state[fdc].address, reg);
 }
 
 static inline bool drive_no_geom(int drive)
@@ -668,16 +667,12 @@ static struct output_log {
 
 static int output_log_pos;
 
-#define current_reqD -1
 #define MAXTIMEOUT -2
 
 static void __reschedule_timeout(int drive, const char *message)
 {
 	unsigned long delay;
 
-	if (drive == current_reqD)
-		drive = current_drive;
-
 	if (drive < 0 || drive >= N_DRIVE) {
 		delay = 20UL * HZ;
 		drive = 0;
@@ -827,59 +822,70 @@ static int set_dor(int fdc, char mask, char data)
 	return olddor;
 }
 
-static void twaddle(void)
+static void twaddle(int fdc, int drive)
 {
-	if (drive_params[current_drive].select_delay)
+	if (drive_params[drive].select_delay)
 		return;
-	fdc_outb(fdc_state[current_fdc].dor & ~(0x10 << UNIT(current_drive)),
-		 current_fdc, FD_DOR);
-	fdc_outb(fdc_state[current_fdc].dor, current_fdc, FD_DOR);
-	drive_state[current_drive].select_date = jiffies;
+	fdc_outb(fdc_state[fdc].dor & ~(0x10 << UNIT(drive)),
+		 fdc, FD_DOR);
+	fdc_outb(fdc_state[fdc].dor, fdc, FD_DOR);
+	drive_state[drive].select_date = jiffies;
 }
 
 /*
- * Reset all driver information about the current fdc.
+ * Reset all driver information about the specified fdc.
  * This is needed after a reset, and after a raw command.
  */
-static void reset_fdc_info(int mode)
+static void reset_fdc_info(int fdc, int mode)
 {
 	int drive;
 
-	fdc_state[current_fdc].spec1 = fdc_state[current_fdc].spec2 = -1;
-	fdc_state[current_fdc].need_configure = 1;
-	fdc_state[current_fdc].perp_mode = 1;
-	fdc_state[current_fdc].rawcmd = 0;
+	fdc_state[fdc].spec1 = fdc_state[fdc].spec2 = -1;
+	fdc_state[fdc].need_configure = 1;
+	fdc_state[fdc].perp_mode = 1;
+	fdc_state[fdc].rawcmd = 0;
 	for (drive = 0; drive < N_DRIVE; drive++)
-		if (FDC(drive) == current_fdc &&
+		if (FDC(drive) == fdc &&
 		    (mode || drive_state[drive].track != NEED_1_RECAL))
 			drive_state[drive].track = NEED_2_RECAL;
 }
 
-/* selects the fdc and drive, and enables the fdc's input/dma. */
+/*
+ * selects the fdc and drive, and enables the fdc's input/dma.
+ * Both current_drive and current_fdc are changed to match the new drive.
+ */
 static void set_fdc(int drive)
 {
-	unsigned int new_fdc = current_fdc;
+	unsigned int fdc;
 
-	if (drive >= 0 && drive < N_DRIVE) {
-		new_fdc = FDC(drive);
-		current_drive = drive;
+	if (drive < 0 || drive >= N_DRIVE) {
+		pr_info("bad drive value %d\n", drive);
+		return;
 	}
-	if (new_fdc >= N_FDC) {
+
+	fdc = FDC(drive);
+	if (fdc >= N_FDC) {
 		pr_info("bad fdc value\n");
 		return;
 	}
-	current_fdc = new_fdc;
-	set_dor(current_fdc, ~0, 8);
+
+	set_dor(fdc, ~0, 8);
 #if N_FDC > 1
-	set_dor(1 - current_fdc, ~8, 0);
+	set_dor(1 - fdc, ~8, 0);
 #endif
-	if (fdc_state[current_fdc].rawcmd == 2)
-		reset_fdc_info(1);
-	if (fdc_inb(current_fdc, FD_STATUS) != STATUS_READY)
-		fdc_state[current_fdc].reset = 1;
+	if (fdc_state[fdc].rawcmd == 2)
+		reset_fdc_info(fdc, 1);
+	if (fdc_inb(fdc, FD_STATUS) != STATUS_READY)
+		fdc_state[fdc].reset = 1;
+
+	current_drive = drive;
+	current_fdc = fdc;
 }
 
-/* locks the driver */
+/*
+ * locks the driver.
+ * Both current_drive and current_fdc are changed to match the new drive.
+ */
 static int lock_fdc(int drive)
 {
 	if (WARN(atomic_read(&usage_count) == 0,
@@ -1062,12 +1068,9 @@ static void setup_DMA(void)
 	unsigned long f;
 
 	if (raw_cmd->length == 0) {
-		int i;
-
-		pr_info("zero dma transfer size:");
-		for (i = 0; i < raw_cmd->cmd_count; i++)
-			pr_cont("%x,", raw_cmd->cmd[i]);
-		pr_cont("\n");
+		print_hex_dump(KERN_INFO, "zero dma transfer size: ",
+			       DUMP_PREFIX_NONE, 16, 1,
+			       raw_cmd->fullcmd, raw_cmd->cmd_count, false);
 		cont->done(0);
 		fdc_state[current_fdc].reset = 1;
 		return;
@@ -1104,62 +1107,62 @@ static void setup_DMA(void)
 #endif
 }
 
-static void show_floppy(void);
+static void show_floppy(int fdc);
 
 /* waits until the fdc becomes ready */
-static int wait_til_ready(void)
+static int wait_til_ready(int fdc)
 {
 	int status;
 	int counter;
 
-	if (fdc_state[current_fdc].reset)
+	if (fdc_state[fdc].reset)
 		return -1;
 	for (counter = 0; counter < 10000; counter++) {
-		status = fdc_inb(current_fdc, FD_STATUS);
+		status = fdc_inb(fdc, FD_STATUS);
 		if (status & STATUS_READY)
 			return status;
 	}
 	if (initialized) {
-		DPRINT("Getstatus times out (%x) on fdc %d\n", status, current_fdc);
-		show_floppy();
+		DPRINT("Getstatus times out (%x) on fdc %d\n", status, fdc);
+		show_floppy(fdc);
 	}
-	fdc_state[current_fdc].reset = 1;
+	fdc_state[fdc].reset = 1;
 	return -1;
 }
 
 /* sends a command byte to the fdc */
-static int output_byte(char byte)
+static int output_byte(int fdc, char byte)
 {
-	int status = wait_til_ready();
+	int status = wait_til_ready(fdc);
 
 	if (status < 0)
 		return -1;
 
 	if (is_ready_state(status)) {
-		fdc_outb(byte, current_fdc, FD_DATA);
+		fdc_outb(byte, fdc, FD_DATA);
 		output_log[output_log_pos].data = byte;
 		output_log[output_log_pos].status = status;
 		output_log[output_log_pos].jiffies = jiffies;
 		output_log_pos = (output_log_pos + 1) % OLOGSIZE;
 		return 0;
 	}
-	fdc_state[current_fdc].reset = 1;
+	fdc_state[fdc].reset = 1;
 	if (initialized) {
 		DPRINT("Unable to send byte %x to FDC. Fdc=%x Status=%x\n",
-		       byte, current_fdc, status);
-		show_floppy();
+		       byte, fdc, status);
+		show_floppy(fdc);
 	}
 	return -1;
 }
 
 /* gets the response from the fdc */
-static int result(void)
+static int result(int fdc)
 {
 	int i;
 	int status = 0;
 
-	for (i = 0; i < MAX_REPLIES; i++) {
-		status = wait_til_ready();
+	for (i = 0; i < FD_RAW_REPLY_SIZE; i++) {
+		status = wait_til_ready(fdc);
 		if (status < 0)
 			break;
 		status &= STATUS_DIR | STATUS_READY | STATUS_BUSY | STATUS_DMA;
@@ -1169,24 +1172,24 @@ static int result(void)
 			return i;
 		}
 		if (status == (STATUS_DIR | STATUS_READY | STATUS_BUSY))
-			reply_buffer[i] = fdc_inb(current_fdc, FD_DATA);
+			reply_buffer[i] = fdc_inb(fdc, FD_DATA);
 		else
 			break;
 	}
 	if (initialized) {
 		DPRINT("get result error. Fdc=%d Last status=%x Read bytes=%d\n",
-		       current_fdc, status, i);
-		show_floppy();
+		       fdc, status, i);
+		show_floppy(fdc);
 	}
-	fdc_state[current_fdc].reset = 1;
+	fdc_state[fdc].reset = 1;
 	return -1;
 }
 
 #define MORE_OUTPUT -2
 /* does the fdc need more output? */
-static int need_more_output(void)
+static int need_more_output(int fdc)
 {
-	int status = wait_til_ready();
+	int status = wait_til_ready(fdc);
 
 	if (status < 0)
 		return -1;
@@ -1194,13 +1197,13 @@ static int need_more_output(void)
 	if (is_ready_state(status))
 		return MORE_OUTPUT;
 
-	return result();
+	return result(fdc);
 }
 
 /* Set perpendicular mode as required, based on data rate, if supported.
  * 82077 Now tested. 1Mbps data rate only possible with 82077-1.
  */
-static void perpendicular_mode(void)
+static void perpendicular_mode(int fdc)
 {
 	unsigned char perp_mode;
 
@@ -1215,7 +1218,7 @@ static void perpendicular_mode(void)
 		default:
 			DPRINT("Invalid data rate for perpendicular mode!\n");
 			cont->done(0);
-			fdc_state[current_fdc].reset = 1;
+			fdc_state[fdc].reset = 1;
 					/*
 					 * convenient way to return to
 					 * redo without too much hassle
@@ -1226,12 +1229,12 @@ static void perpendicular_mode(void)
 	} else
 		perp_mode = 0;
 
-	if (fdc_state[current_fdc].perp_mode == perp_mode)
+	if (fdc_state[fdc].perp_mode == perp_mode)
 		return;
-	if (fdc_state[current_fdc].version >= FDC_82077_ORIG) {
-		output_byte(FD_PERPENDICULAR);
-		output_byte(perp_mode);
-		fdc_state[current_fdc].perp_mode = perp_mode;
+	if (fdc_state[fdc].version >= FDC_82077_ORIG) {
+		output_byte(fdc, FD_PERPENDICULAR);
+		output_byte(fdc, perp_mode);
+		fdc_state[fdc].perp_mode = perp_mode;
 	} else if (perp_mode) {
 		DPRINT("perpendicular mode not supported by this FDC.\n");
 	}
@@ -1240,16 +1243,15 @@ static void perpendicular_mode(void)
 static int fifo_depth = 0xa;
 static int no_fifo;
 
-static int fdc_configure(void)
+static int fdc_configure(int fdc)
 {
 	/* Turn on FIFO */
-	output_byte(FD_CONFIGURE);
-	if (need_more_output() != MORE_OUTPUT)
+	output_byte(fdc, FD_CONFIGURE);
+	if (need_more_output(fdc) != MORE_OUTPUT)
 		return 0;
-	output_byte(0);
-	output_byte(0x10 | (no_fifo & 0x20) | (fifo_depth & 0xf));
-	output_byte(0);		/* pre-compensation from track
-				   0 upwards */
+	output_byte(fdc, 0);
+	output_byte(fdc, 0x10 | (no_fifo & 0x20) | (fifo_depth & 0xf));
+	output_byte(fdc, 0);    /* pre-compensation from track 0 upwards */
 	return 1;
 }
 
@@ -1274,7 +1276,7 @@ static int fdc_configure(void)
  *
  * These values are rounded up to the next highest available delay time.
  */
-static void fdc_specify(void)
+static void fdc_specify(int fdc, int drive)
 {
 	unsigned char spec1;
 	unsigned char spec2;
@@ -1286,10 +1288,10 @@ static void fdc_specify(void)
 	int hlt_max_code = 0x7f;
 	int hut_max_code = 0xf;
 
-	if (fdc_state[current_fdc].need_configure &&
-	    fdc_state[current_fdc].version >= FDC_82072A) {
-		fdc_configure();
-		fdc_state[current_fdc].need_configure = 0;
+	if (fdc_state[fdc].need_configure &&
+	    fdc_state[fdc].version >= FDC_82072A) {
+		fdc_configure(fdc);
+		fdc_state[fdc].need_configure = 0;
 	}
 
 	switch (raw_cmd->rate & 0x03) {
@@ -1298,13 +1300,13 @@ static void fdc_specify(void)
 		break;
 	case 1:
 		dtr = 300;
-		if (fdc_state[current_fdc].version >= FDC_82078) {
+		if (fdc_state[fdc].version >= FDC_82078) {
 			/* chose the default rate table, not the one
 			 * where 1 = 2 Mbps */
-			output_byte(FD_DRIVESPEC);
-			if (need_more_output() == MORE_OUTPUT) {
-				output_byte(UNIT(current_drive));
-				output_byte(0xc0);
+			output_byte(fdc, FD_DRIVESPEC);
+			if (need_more_output(fdc) == MORE_OUTPUT) {
+				output_byte(fdc, UNIT(drive));
+				output_byte(fdc, 0xc0);
 			}
 		}
 		break;
@@ -1313,14 +1315,14 @@ static void fdc_specify(void)
 		break;
 	}
 
-	if (fdc_state[current_fdc].version >= FDC_82072) {
+	if (fdc_state[fdc].version >= FDC_82072) {
 		scale_dtr = dtr;
 		hlt_max_code = 0x00;	/* 0==256msec*dtr0/dtr (not linear!) */
 		hut_max_code = 0x0;	/* 0==256msec*dtr0/dtr (not linear!) */
 	}
 
 	/* Convert step rate from microseconds to milliseconds and 4 bits */
-	srt = 16 - DIV_ROUND_UP(drive_params[current_drive].srt * scale_dtr / 1000,
+	srt = 16 - DIV_ROUND_UP(drive_params[drive].srt * scale_dtr / 1000,
 				NOMINAL_DTR);
 	if (slow_floppy)
 		srt = srt / 4;
@@ -1328,14 +1330,14 @@ static void fdc_specify(void)
 	SUPBOUND(srt, 0xf);
 	INFBOUND(srt, 0);
 
-	hlt = DIV_ROUND_UP(drive_params[current_drive].hlt * scale_dtr / 2,
+	hlt = DIV_ROUND_UP(drive_params[drive].hlt * scale_dtr / 2,
 			   NOMINAL_DTR);
 	if (hlt < 0x01)
 		hlt = 0x01;
 	else if (hlt > 0x7f)
 		hlt = hlt_max_code;
 
-	hut = DIV_ROUND_UP(drive_params[current_drive].hut * scale_dtr / 16,
+	hut = DIV_ROUND_UP(drive_params[drive].hut * scale_dtr / 16,
 			   NOMINAL_DTR);
 	if (hut < 0x1)
 		hut = 0x1;
@@ -1346,12 +1348,12 @@ static void fdc_specify(void)
 	spec2 = (hlt << 1) | (use_virtual_dma & 1);
 
 	/* If these parameters did not change, just return with success */
-	if (fdc_state[current_fdc].spec1 != spec1 ||
-	    fdc_state[current_fdc].spec2 != spec2) {
+	if (fdc_state[fdc].spec1 != spec1 ||
+	    fdc_state[fdc].spec2 != spec2) {
 		/* Go ahead and set spec1 and spec2 */
-		output_byte(FD_SPECIFY);
-		output_byte(fdc_state[current_fdc].spec1 = spec1);
-		output_byte(fdc_state[current_fdc].spec2 = spec2);
+		output_byte(fdc, FD_SPECIFY);
+		output_byte(fdc, fdc_state[fdc].spec1 = spec1);
+		output_byte(fdc, fdc_state[fdc].spec2 = spec2);
 	}
 }				/* fdc_specify */
 
@@ -1513,7 +1515,7 @@ static void setup_rw_floppy(void)
 
 	r = 0;
 	for (i = 0; i < raw_cmd->cmd_count; i++)
-		r |= output_byte(raw_cmd->cmd[i]);
+		r |= output_byte(current_fdc, raw_cmd->fullcmd[i]);
 
 	debugt(__func__, "rw_command");
 
@@ -1524,7 +1526,7 @@ static void setup_rw_floppy(void)
 	}
 
 	if (!(flags & FD_RAW_INTR)) {
-		inr = result();
+		inr = result(current_fdc);
 		cont->interrupt();
 	} else if (flags & FD_RAW_NEED_DISK)
 		fd_watchdog();
@@ -1562,29 +1564,29 @@ static void seek_interrupt(void)
 	floppy_ready();
 }
 
-static void check_wp(void)
+static void check_wp(int fdc, int drive)
 {
-	if (test_bit(FD_VERIFY_BIT, &drive_state[current_drive].flags)) {
+	if (test_bit(FD_VERIFY_BIT, &drive_state[drive].flags)) {
 					/* check write protection */
-		output_byte(FD_GETSTATUS);
-		output_byte(UNIT(current_drive));
-		if (result() != 1) {
-			fdc_state[current_fdc].reset = 1;
+		output_byte(fdc, FD_GETSTATUS);
+		output_byte(fdc, UNIT(drive));
+		if (result(fdc) != 1) {
+			fdc_state[fdc].reset = 1;
 			return;
 		}
-		clear_bit(FD_VERIFY_BIT, &drive_state[current_drive].flags);
+		clear_bit(FD_VERIFY_BIT, &drive_state[drive].flags);
 		clear_bit(FD_NEED_TWADDLE_BIT,
-			  &drive_state[current_drive].flags);
-		debug_dcl(drive_params[current_drive].flags,
+			  &drive_state[drive].flags);
+		debug_dcl(drive_params[drive].flags,
 			  "checking whether disk is write protected\n");
-		debug_dcl(drive_params[current_drive].flags, "wp=%x\n",
+		debug_dcl(drive_params[drive].flags, "wp=%x\n",
 			  reply_buffer[ST3] & 0x40);
 		if (!(reply_buffer[ST3] & 0x40))
 			set_bit(FD_DISK_WRITABLE_BIT,
-				&drive_state[current_drive].flags);
+				&drive_state[drive].flags);
 		else
 			clear_bit(FD_DISK_WRITABLE_BIT,
-				  &drive_state[current_drive].flags);
+				  &drive_state[drive].flags);
 	}
 }
 
@@ -1628,7 +1630,7 @@ static void seek_floppy(void)
 			track = 1;
 		}
 	} else {
-		check_wp();
+		check_wp(current_fdc, current_drive);
 		if (raw_cmd->track != drive_state[current_drive].track &&
 		    (raw_cmd->flags & FD_RAW_NEED_SEEK))
 			track = raw_cmd->track;
@@ -1639,9 +1641,9 @@ static void seek_floppy(void)
 	}
 
 	do_floppy = seek_interrupt;
-	output_byte(FD_SEEK);
-	output_byte(UNIT(current_drive));
-	if (output_byte(track) < 0) {
+	output_byte(current_fdc, FD_SEEK);
+	output_byte(current_fdc, UNIT(current_drive));
+	if (output_byte(current_fdc, track) < 0) {
 		reset_fdc();
 		return;
 	}
@@ -1742,14 +1744,14 @@ irqreturn_t floppy_interrupt(int irq, void *dev_id)
 
 	do_print = !handler && print_unex && initialized;
 
-	inr = result();
+	inr = result(current_fdc);
 	if (do_print)
 		print_result("unexpected interrupt", inr);
 	if (inr == 0) {
 		int max_sensei = 4;
 		do {
-			output_byte(FD_SENSEI);
-			inr = result();
+			output_byte(current_fdc, FD_SENSEI);
+			inr = result(current_fdc);
 			if (do_print)
 				print_result("sensei", inr);
 			max_sensei--;
@@ -1771,8 +1773,8 @@ static void recalibrate_floppy(void)
 {
 	debugt(__func__, "");
 	do_floppy = recal_interrupt;
-	output_byte(FD_RECALIBRATE);
-	if (output_byte(UNIT(current_drive)) < 0)
+	output_byte(current_fdc, FD_RECALIBRATE);
+	if (output_byte(current_fdc, UNIT(current_drive)) < 0)
 		reset_fdc();
 }
 
@@ -1782,7 +1784,7 @@ static void recalibrate_floppy(void)
 static void reset_interrupt(void)
 {
 	debugt(__func__, "");
-	result();		/* get the status ready for set_fdc */
+	result(current_fdc);		/* get the status ready for set_fdc */
 	if (fdc_state[current_fdc].reset) {
 		pr_info("reset set in interrupt, calling %ps\n", cont->error);
 		cont->error();	/* a reset just after a reset. BAD! */
@@ -1792,7 +1794,9 @@ static void reset_interrupt(void)
 
 /*
  * reset is done by pulling bit 2 of DOR low for a while (old FDCs),
- * or by setting the self clearing bit 7 of STATUS (newer FDCs)
+ * or by setting the self clearing bit 7 of STATUS (newer FDCs).
+ * This WILL trigger an interrupt, causing the handlers in the current
+ * cont's ->redo() to be called via reset_interrupt().
  */
 static void reset_fdc(void)
 {
@@ -1800,7 +1804,7 @@ static void reset_fdc(void)
 
 	do_floppy = reset_interrupt;
 	fdc_state[current_fdc].reset = 0;
-	reset_fdc_info(0);
+	reset_fdc_info(current_fdc, 0);
 
 	/* Pseudo-DMA may intercept 'reset finished' interrupt.  */
 	/* Irrelevant for systems with true DMA (i386).          */
@@ -1819,7 +1823,7 @@ static void reset_fdc(void)
 	}
 }
 
-static void show_floppy(void)
+static void show_floppy(int fdc)
 {
 	int i;
 
@@ -1842,7 +1846,7 @@ static void show_floppy(void)
 	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1,
 		       reply_buffer, resultsize, true);
 
-	pr_info("status=%x\n", fdc_inb(current_fdc, FD_STATUS));
+	pr_info("status=%x\n", fdc_inb(fdc, FD_STATUS));
 	pr_info("fdc_busy=%lu\n", fdc_busy);
 	if (do_floppy)
 		pr_info("do_floppy=%ps\n", do_floppy);
@@ -1868,7 +1872,7 @@ static void floppy_shutdown(struct work_struct *arg)
 	unsigned long flags;
 
 	if (initialized)
-		show_floppy();
+		show_floppy(current_fdc);
 	cancel_activity();
 
 	flags = claim_dma_lock();
@@ -1934,7 +1938,7 @@ static void floppy_ready(void)
 		  "calling disk change from floppy_ready\n");
 	if (!(raw_cmd->flags & FD_RAW_NO_MOTOR) &&
 	    disk_change(current_drive) && !drive_params[current_drive].select_delay)
-		twaddle();	/* this clears the dcl on certain
+		twaddle(current_fdc, current_drive);	/* this clears the dcl on certain
 				 * drive/controller combinations */
 
 #ifdef fd_chose_dma_mode
@@ -1946,20 +1950,20 @@ static void floppy_ready(void)
 #endif
 
 	if (raw_cmd->flags & (FD_RAW_NEED_SEEK | FD_RAW_NEED_DISK)) {
-		perpendicular_mode();
-		fdc_specify();	/* must be done here because of hut, hlt ... */
+		perpendicular_mode(current_fdc);
+		fdc_specify(current_fdc, current_drive); /* must be done here because of hut, hlt ... */
 		seek_floppy();
 	} else {
 		if ((raw_cmd->flags & FD_RAW_READ) ||
 		    (raw_cmd->flags & FD_RAW_WRITE))
-			fdc_specify();
+			fdc_specify(current_fdc, current_drive);
 		setup_rw_floppy();
 	}
 }
 
 static void floppy_start(void)
 {
-	reschedule_timeout(current_reqD, "floppy start");
+	reschedule_timeout(current_drive, "floppy start");
 
 	scandrives();
 	debug_dcl(drive_params[current_drive].flags,
@@ -2004,6 +2008,9 @@ static const struct cont_t intr_cont = {
 	.done		= (done_f)empty
 };
 
+/* schedules handler, waiting for completion. May be interrupted, will then
+ * return -EINTR, in which case the driver will automatically be unlocked.
+ */
 static int wait_til_done(void (*handler)(void), bool interruptible)
 {
 	int ret;
@@ -2059,18 +2066,19 @@ static void success_and_wakeup(void)
  * ==========================
  */
 
-static int next_valid_format(void)
+static int next_valid_format(int drive)
 {
 	int probed_format;
 
-	probed_format = drive_state[current_drive].probed_format;
+	probed_format = drive_state[drive].probed_format;
 	while (1) {
-		if (probed_format >= 8 || !drive_params[current_drive].autodetect[probed_format]) {
-			drive_state[current_drive].probed_format = 0;
+		if (probed_format >= FD_AUTODETECT_SIZE ||
+		    !drive_params[drive].autodetect[probed_format]) {
+			drive_state[drive].probed_format = 0;
 			return 1;
 		}
-		if (floppy_type[drive_params[current_drive].autodetect[probed_format]].sect) {
-			drive_state[current_drive].probed_format = probed_format;
+		if (floppy_type[drive_params[drive].autodetect[probed_format]].sect) {
+			drive_state[drive].probed_format = probed_format;
 			return 0;
 		}
 		probed_format++;
@@ -2083,7 +2091,7 @@ static void bad_flp_intr(void)
 
 	if (probing) {
 		drive_state[current_drive].probed_format++;
-		if (!next_valid_format())
+		if (!next_valid_format(current_drive))
 			return;
 	}
 	err_count = ++(*errors);
@@ -2843,6 +2851,9 @@ static int set_next_request(void)
 	return current_req != NULL;
 }
 
+/* Starts or continues processing request. Will automatically unlock the
+ * driver at end of request.
+ */
 static void redo_fd_request(void)
 {
 	int drive;
@@ -2867,7 +2878,7 @@ do_request:
 	}
 	drive = (long)current_req->rq_disk->private_data;
 	set_fdc(drive);
-	reschedule_timeout(current_reqD, "redo fd request");
+	reschedule_timeout(current_drive, "redo fd request");
 
 	set_floppy(drive);
 	raw_cmd = &default_raw_cmd;
@@ -2885,7 +2896,7 @@ do_request:
 	if (!_floppy) {	/* Autodetection */
 		if (!probing) {
 			drive_state[current_drive].probed_format = 0;
-			if (next_valid_format()) {
+			if (next_valid_format(current_drive)) {
 				DPRINT("no autodetectable formats\n");
 				_floppy = NULL;
 				request_done(0);
@@ -2904,7 +2915,7 @@ do_request:
 	}
 
 	if (test_bit(FD_NEED_TWADDLE_BIT, &drive_state[current_drive].flags))
-		twaddle();
+		twaddle(current_fdc, current_drive);
 	schedule_bh(floppy_start);
 	debugt(__func__, "queue fd request");
 	return;
@@ -2917,6 +2928,7 @@ static const struct cont_t rw_cont = {
 	.done		= request_done
 };
 
+/* schedule the request and automatically unlock the driver on completion */
 static void process_fd_request(void)
 {
 	cont = &rw_cont;
@@ -2996,6 +3008,10 @@ static const struct cont_t reset_cont = {
 	.done		= generic_done
 };
 
+/*
+ * Resets the FDC connected to drive <drive>.
+ * Both current_drive and current_fdc are changed to match the new drive.
+ */
 static int user_reset_fdc(int drive, int arg, bool interruptible)
 {
 	int ret;
@@ -3006,6 +3022,9 @@ static int user_reset_fdc(int drive, int arg, bool interruptible)
 	if (arg == FD_RESET_ALWAYS)
 		fdc_state[current_fdc].reset = 1;
 	if (fdc_state[current_fdc].reset) {
+		/* note: reset_fdc will take care of unlocking the driver
+		 * on completion.
+		 */
 		cont = &reset_cont;
 		ret = wait_til_done(reset_fdc, interruptible);
 		if (ret == -EINTR)
@@ -3059,7 +3078,7 @@ static void raw_cmd_done(int flag)
 		raw_cmd->flags |= FD_RAW_HARDFAILURE;
 	} else {
 		raw_cmd->reply_count = inr;
-		if (raw_cmd->reply_count > MAX_REPLIES)
+		if (raw_cmd->reply_count > FD_RAW_REPLY_SIZE)
 			raw_cmd->reply_count = 0;
 		for (i = 0; i < raw_cmd->reply_count; i++)
 			raw_cmd->reply[i] = reply_buffer[i];
@@ -3170,18 +3189,10 @@ loop:
 	if (ret)
 		return -EFAULT;
 	param += sizeof(struct floppy_raw_cmd);
-	if (ptr->cmd_count > 33)
-			/* the command may now also take up the space
-			 * initially intended for the reply & the
-			 * reply count. Needed for long 82078 commands
-			 * such as RESTORE, which takes ... 17 command
-			 * bytes. Murphy's law #137: When you reserve
-			 * 16 bytes for a structure, you'll one day
-			 * discover that you really need 17...
-			 */
+	if (ptr->cmd_count > FD_RAW_CMD_FULLSIZE)
 		return -EINVAL;
 
-	for (i = 0; i < 16; i++)
+	for (i = 0; i < FD_RAW_REPLY_SIZE; i++)
 		ptr->reply[i] = 0;
 	ptr->resultcode = 0;
 
@@ -3423,13 +3434,13 @@ static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return 0;
 }
 
-static bool valid_floppy_drive_params(const short autodetect[8],
+static bool valid_floppy_drive_params(const short autodetect[FD_AUTODETECT_SIZE],
 		int native_format)
 {
 	size_t floppy_type_size = ARRAY_SIZE(floppy_type);
 	size_t i = 0;
 
-	for (i = 0; i < 8; ++i) {
+	for (i = 0; i < FD_AUTODETECT_SIZE; ++i) {
 		if (autodetect[i] < 0 ||
 		    autodetect[i] >= floppy_type_size)
 			return false;
@@ -3610,7 +3621,7 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, unsigned int
 	case FDTWADDLE:
 		if (lock_fdc(drive))
 			return -EINTR;
-		twaddle();
+		twaddle(current_fdc, current_drive);
 		process_fd_request();
 		return 0;
 	default:
@@ -3654,7 +3665,7 @@ struct compat_floppy_drive_params {
 	struct floppy_max_errors max_errors;
 	char		flags;
 	char		read_track;
-	short		autodetect[8];
+	short		autodetect[FD_AUTODETECT_SIZE];
 	compat_int_t	checkfreq;
 	compat_int_t	native_format;
 };
@@ -4298,79 +4309,79 @@ static const struct block_device_operations floppy_fops = {
 
 /* Determine the floppy disk controller type */
 /* This routine was written by David C. Niemi */
-static char __init get_fdc_version(void)
+static char __init get_fdc_version(int fdc)
 {
 	int r;
 
-	output_byte(FD_DUMPREGS);	/* 82072 and better know DUMPREGS */
-	if (fdc_state[current_fdc].reset)
+	output_byte(fdc, FD_DUMPREGS);	/* 82072 and better know DUMPREGS */
+	if (fdc_state[fdc].reset)
 		return FDC_NONE;
-	r = result();
+	r = result(fdc);
 	if (r <= 0x00)
 		return FDC_NONE;	/* No FDC present ??? */
 	if ((r == 1) && (reply_buffer[0] == 0x80)) {
-		pr_info("FDC %d is an 8272A\n", current_fdc);
+		pr_info("FDC %d is an 8272A\n", fdc);
 		return FDC_8272A;	/* 8272a/765 don't know DUMPREGS */
 	}
 	if (r != 10) {
 		pr_info("FDC %d init: DUMPREGS: unexpected return of %d bytes.\n",
-			current_fdc, r);
+			fdc, r);
 		return FDC_UNKNOWN;
 	}
 
-	if (!fdc_configure()) {
-		pr_info("FDC %d is an 82072\n", current_fdc);
+	if (!fdc_configure(fdc)) {
+		pr_info("FDC %d is an 82072\n", fdc);
 		return FDC_82072;	/* 82072 doesn't know CONFIGURE */
 	}
 
-	output_byte(FD_PERPENDICULAR);
-	if (need_more_output() == MORE_OUTPUT) {
-		output_byte(0);
+	output_byte(fdc, FD_PERPENDICULAR);
+	if (need_more_output(fdc) == MORE_OUTPUT) {
+		output_byte(fdc, 0);
 	} else {
-		pr_info("FDC %d is an 82072A\n", current_fdc);
+		pr_info("FDC %d is an 82072A\n", fdc);
 		return FDC_82072A;	/* 82072A as found on Sparcs. */
 	}
 
-	output_byte(FD_UNLOCK);
-	r = result();
+	output_byte(fdc, FD_UNLOCK);
+	r = result(fdc);
 	if ((r == 1) && (reply_buffer[0] == 0x80)) {
-		pr_info("FDC %d is a pre-1991 82077\n", current_fdc);
+		pr_info("FDC %d is a pre-1991 82077\n", fdc);
 		return FDC_82077_ORIG;	/* Pre-1991 82077, doesn't know
 					 * LOCK/UNLOCK */
 	}
 	if ((r != 1) || (reply_buffer[0] != 0x00)) {
 		pr_info("FDC %d init: UNLOCK: unexpected return of %d bytes.\n",
-			current_fdc, r);
+			fdc, r);
 		return FDC_UNKNOWN;
 	}
-	output_byte(FD_PARTID);
-	r = result();
+	output_byte(fdc, FD_PARTID);
+	r = result(fdc);
 	if (r != 1) {
 		pr_info("FDC %d init: PARTID: unexpected return of %d bytes.\n",
-			current_fdc, r);
+			fdc, r);
 		return FDC_UNKNOWN;
 	}
 	if (reply_buffer[0] == 0x80) {
-		pr_info("FDC %d is a post-1991 82077\n", current_fdc);
+		pr_info("FDC %d is a post-1991 82077\n", fdc);
 		return FDC_82077;	/* Revised 82077AA passes all the tests */
 	}
 	switch (reply_buffer[0] >> 5) {
 	case 0x0:
 		/* Either a 82078-1 or a 82078SL running at 5Volt */
-		pr_info("FDC %d is an 82078.\n", current_fdc);
+		pr_info("FDC %d is an 82078.\n", fdc);
 		return FDC_82078;
 	case 0x1:
-		pr_info("FDC %d is a 44pin 82078\n", current_fdc);
+		pr_info("FDC %d is a 44pin 82078\n", fdc);
 		return FDC_82078;
 	case 0x2:
-		pr_info("FDC %d is a S82078B\n", current_fdc);
+		pr_info("FDC %d is a S82078B\n", fdc);
 		return FDC_S82078B;
 	case 0x3:
-		pr_info("FDC %d is a National Semiconductor PC87306\n", current_fdc);
+		pr_info("FDC %d is a National Semiconductor PC87306\n", fdc);
 		return FDC_87306;
 	default:
 		pr_info("FDC %d init: 82078 variant with unknown PARTID=%d.\n",
-			current_fdc, reply_buffer[0] >> 5);
+			fdc, reply_buffer[0] >> 5);
 		return FDC_82078_UNKN;
 	}
 }				/* get_fdc_version */
@@ -4534,11 +4545,13 @@ static void floppy_device_release(struct device *dev)
 static int floppy_resume(struct device *dev)
 {
 	int fdc;
+	int saved_drive;
 
+	saved_drive = current_drive;
 	for (fdc = 0; fdc < N_FDC; fdc++)
 		if (fdc_state[fdc].address != -1)
-			user_reset_fdc(-1, FD_RESET_ALWAYS, false);
-
+			user_reset_fdc(REVDRIVE(fdc, 0), FD_RESET_ALWAYS, false);
+	set_fdc(saved_drive);
 	return 0;
 }
 
@@ -4646,16 +4659,15 @@ static int __init do_floppy_init(void)
 	config_types();
 
 	for (i = 0; i < N_FDC; i++) {
-		current_fdc = i;
-		memset(&fdc_state[current_fdc], 0, sizeof(*fdc_state));
-		fdc_state[current_fdc].dtr = -1;
-		fdc_state[current_fdc].dor = 0x4;
+		memset(&fdc_state[i], 0, sizeof(*fdc_state));
+		fdc_state[i].dtr = -1;
+		fdc_state[i].dor = 0x4;
 #if defined(__sparc__) || defined(__mc68000__)
 	/*sparcs/sun3x don't have a DOR reset which we can fall back on to */
 #ifdef __mc68000__
 		if (MACH_IS_SUN3X)
 #endif
-			fdc_state[current_fdc].version = FDC_82072A;
+			fdc_state[i].version = FDC_82072A;
 #endif
 	}
 
@@ -4697,30 +4709,29 @@ static int __init do_floppy_init(void)
 	msleep(10);
 
 	for (i = 0; i < N_FDC; i++) {
-		current_fdc = i;
-		fdc_state[current_fdc].driver_version = FD_DRIVER_VERSION;
+		fdc_state[i].driver_version = FD_DRIVER_VERSION;
 		for (unit = 0; unit < 4; unit++)
-			fdc_state[current_fdc].track[unit] = 0;
-		if (fdc_state[current_fdc].address == -1)
+			fdc_state[i].track[unit] = 0;
+		if (fdc_state[i].address == -1)
 			continue;
-		fdc_state[current_fdc].rawcmd = 2;
-		if (user_reset_fdc(-1, FD_RESET_ALWAYS, false)) {
+		fdc_state[i].rawcmd = 2;
+		if (user_reset_fdc(REVDRIVE(i, 0), FD_RESET_ALWAYS, false)) {
 			/* free ioports reserved by floppy_grab_irq_and_dma() */
-			floppy_release_regions(current_fdc);
-			fdc_state[current_fdc].address = -1;
-			fdc_state[current_fdc].version = FDC_NONE;
+			floppy_release_regions(i);
+			fdc_state[i].address = -1;
+			fdc_state[i].version = FDC_NONE;
 			continue;
 		}
 		/* Try to determine the floppy controller type */
-		fdc_state[current_fdc].version = get_fdc_version();
-		if (fdc_state[current_fdc].version == FDC_NONE) {
+		fdc_state[i].version = get_fdc_version(i);
+		if (fdc_state[i].version == FDC_NONE) {
 			/* free ioports reserved by floppy_grab_irq_and_dma() */
-			floppy_release_regions(current_fdc);
-			fdc_state[current_fdc].address = -1;
+			floppy_release_regions(i);
+			fdc_state[i].address = -1;
 			continue;
 		}
 		if (can_use_virtual_dma == 2 &&
-		    fdc_state[current_fdc].version < FDC_82072A)
+		    fdc_state[i].version < FDC_82072A)
 			can_use_virtual_dma = 0;
 
 		have_no_fdc = 0;
@@ -4728,7 +4739,7 @@ static int __init do_floppy_init(void)
 		 * properly, so force a reset for the standard FDC clones,
 		 * to avoid interrupt garbage.
 		 */
-		user_reset_fdc(-1, FD_RESET_ALWAYS, false);
+		user_reset_fdc(REVDRIVE(i, 0), FD_RESET_ALWAYS, false);
 	}
 	current_fdc = 0;
 	cancel_delayed_work(&fd_timeout);
@@ -4855,6 +4866,8 @@ static void floppy_release_regions(int fdc)
 
 static int floppy_grab_irq_and_dma(void)
 {
+	int fdc;
+
 	if (atomic_inc_return(&usage_count) > 1)
 		return 0;
 
@@ -4882,24 +4895,24 @@ static int floppy_grab_irq_and_dma(void)
 		}
 	}
 
-	for (current_fdc = 0; current_fdc < N_FDC; current_fdc++) {
-		if (fdc_state[current_fdc].address != -1) {
-			if (floppy_request_regions(current_fdc))
+	for (fdc = 0; fdc < N_FDC; fdc++) {
+		if (fdc_state[fdc].address != -1) {
+			if (floppy_request_regions(fdc))
 				goto cleanup;
 		}
 	}
-	for (current_fdc = 0; current_fdc < N_FDC; current_fdc++) {
-		if (fdc_state[current_fdc].address != -1) {
-			reset_fdc_info(1);
-			fdc_outb(fdc_state[current_fdc].dor, current_fdc, FD_DOR);
+	for (fdc = 0; fdc < N_FDC; fdc++) {
+		if (fdc_state[fdc].address != -1) {
+			reset_fdc_info(fdc, 1);
+			fdc_outb(fdc_state[fdc].dor, fdc, FD_DOR);
 		}
 	}
-	current_fdc = 0;
+
 	set_dor(0, ~0, 8);	/* avoid immediate interrupt */
 
-	for (current_fdc = 0; current_fdc < N_FDC; current_fdc++)
-		if (fdc_state[current_fdc].address != -1)
-			fdc_outb(fdc_state[current_fdc].dor, current_fdc, FD_DOR);
+	for (fdc = 0; fdc < N_FDC; fdc++)
+		if (fdc_state[fdc].address != -1)
+			fdc_outb(fdc_state[fdc].dor, fdc, FD_DOR);
 	/*
 	 * The driver will try and free resources and relies on us
 	 * to know if they were allocated or not.
@@ -4910,15 +4923,16 @@ static int floppy_grab_irq_and_dma(void)
 cleanup:
 	fd_free_irq();
 	fd_free_dma();
-	while (--current_fdc >= 0)
-		floppy_release_regions(current_fdc);
+	while (--fdc >= 0)
+		floppy_release_regions(fdc);
+	current_fdc = 0;
 	atomic_dec(&usage_count);
 	return -1;
 }
 
 static void floppy_release_irq_and_dma(void)
 {
-	int old_fdc;
+	int fdc;
 #ifndef __sparc__
 	int drive;
 #endif
@@ -4959,11 +4973,9 @@ static void floppy_release_irq_and_dma(void)
 		pr_info("auxiliary floppy timer still active\n");
 	if (work_pending(&floppy_work))
 		pr_info("work still pending\n");
-	old_fdc = current_fdc;
-	for (current_fdc = 0; current_fdc < N_FDC; current_fdc++)
-		if (fdc_state[current_fdc].address != -1)
-			floppy_release_regions(current_fdc);
-	current_fdc = old_fdc;
+	for (fdc = 0; fdc < N_FDC; fdc++)
+		if (fdc_state[fdc].address != -1)
+			floppy_release_regions(fdc);
 }
 
 #ifdef MODULE
diff --git a/include/uapi/linux/fd.h b/include/uapi/linux/fd.h
index 90fb94712c41..8b80c63b971c 100644
--- a/include/uapi/linux/fd.h
+++ b/include/uapi/linux/fd.h
@@ -172,7 +172,10 @@ struct floppy_drive_params {
  * used in succession to try to read the disk. If the FDC cannot lock onto
  * the disk, the next format is tried. This uses the variable 'probing'.
  */
-	short autodetect[8];		/* autodetected formats */
+
+#define FD_AUTODETECT_SIZE 8
+
+	short autodetect[FD_AUTODETECT_SIZE]; /* autodetected formats */
 	
 	int checkfreq; /* how often should the drive be checked for disk 
 			* changes */
@@ -357,10 +360,25 @@ struct floppy_raw_cmd {
 	int buffer_length; /* length of allocated buffer */
 
 	unsigned char rate;
+
+#define FD_RAW_CMD_SIZE 16
+#define FD_RAW_REPLY_SIZE 16
+#define FD_RAW_CMD_FULLSIZE (FD_RAW_CMD_SIZE + 1 + FD_RAW_REPLY_SIZE)
+
+	/* The command may take up the space initially intended for the reply
+	 * and the reply count. Needed for long 82078 commands such as RESTORE,
+	 * which takes 17 command bytes.
+	 */
+
 	unsigned char cmd_count;
-	unsigned char cmd[16];
-	unsigned char reply_count;
-	unsigned char reply[16];
+	union {
+		struct {
+			unsigned char cmd[FD_RAW_CMD_SIZE];
+			unsigned char reply_count;
+			unsigned char reply[FD_RAW_REPLY_SIZE];
+		};
+		unsigned char fullcmd[FD_RAW_CMD_FULLSIZE];
+	};
 	int track;
 	int resultcode;
 
diff --git a/include/uapi/linux/fdreg.h b/include/uapi/linux/fdreg.h
index 1318881954e1..10d33632939d 100644
--- a/include/uapi/linux/fdreg.h
+++ b/include/uapi/linux/fdreg.h
@@ -7,13 +7,23 @@
  * Handbook", Sanches and Canton.
  */
 
-/* Fd controller regs. S&C, about page 340 */
-#define FD_STATUS	4
-#define FD_DATA		5
+/* 82077's auxiliary status registers A & B (R) */
+#define FD_SRA		0
+#define FD_SRB		1
 
 /* Digital Output Register */
 #define FD_DOR		2
 
+/* 82077's tape drive register (R/W) */
+#define FD_TDR		3
+
+/* 82077's data rate select register (W) */
+#define FD_DSR		4
+
+/* Fd controller regs. S&C, about page 340 */
+#define FD_STATUS	4
+#define FD_DATA		5
+
 /* Digital Input Register (read) */
 #define FD_DIR		7