configs: bump ARC axs10x Linux kernel and headers to 4.2 release

Linux kernel 4.2 was finally released, so bumping from 4.2-rc5 to
final release.

Updating Linux headers to 4.2 branch since they are introduced in
Buildroot as well already.

Also adding 1 back-ported patch that makes SD/MMC cards usable on AXS
boards.  This patch will be a part of 4.3 (already in linux-next) and
hopefully will make its way in 4.2.1.

Once that patch appears in 4.2.x it can be removed from here.

Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

1 files changed, 198 insertions, 0 deletions

diff --git a/board/synopsys/axs10x/patches/linux/0001-mmc-dw_mmc-handle-data-blocks-than-4kB-if-IDMAC-is-u.patch b/board/synopsys/axs10x/patches/linux/0001-mmc-dw_mmc-handle-data-blocks-than-4kB-if-IDMAC-is-u.patch
new file mode 100644
index 000000000..93986b059
--- /dev/null
+++ b/board/synopsys/axs10x/patches/linux/0001-mmc-dw_mmc-handle-data-blocks-than-4kB-if-IDMAC-is-u.patch
@@ -0,0 +1,198 @@
+From 969872e334937bd0956887a925f20f7a446af5f6 Mon Sep 17 00:00:00 2001
+From: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
+Date: Thu, 25 Jun 2015 11:25:07 +0300
+Subject: [PATCH] mmc: dw_mmc: handle data blocks > than 4kB if IDMAC is used
+
+As per DW MobileStorage databook "each descriptor can transfer up to 4kB
+of data in chained mode", moreover buffer size that is put in "des1" is
+limited to 13 bits, i.e. for example on attempt to
+IDMAC_SET_BUFFER1_SIZE(desc, 8192) size value that's effectively written
+will be 0.
+
+On the platform with 8kB PAGE_SIZE I see dw_mmc gets data blocks in
+SG-list of 8kB size and that leads to unpredictable behavior of the
+SD/MMC controller.
+
+In particular on write to FAT partition of SD-card the controller will
+stuck in the middle of DMA transaction.
+
+Solution to the problem is simple - we need to pass large (> 4kB) data
+buffers to the controller via multiple descriptors. And that's what
+that change does.
+
+What's interesting I did try original driver on same platform but
+configured with 4kB PAGE_SIZE and may confirm that data blocks passed
+in SG-list to dw_mmc never exeed 4kB limit - that explains why nobody
+ever faced a problem I did.
+
+Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
+Cc: Seungwon Jeon <tgih.jun@samsung.com>
+Cc: Jaehoon Chung <jh80.chung@samsung.com>
+Cc: Ulf Hansson <ulf.hansson@linaro.org>
+Cc: arc-linux-dev@synopsys.com
+Cc: linux-kernel@vger.kernel.org
+Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
+---
+ drivers/mmc/host/dw_mmc.c | 109 ++++++++++++++++++++++++++++++----------------
+ 1 file changed, 71 insertions(+), 38 deletions(-)
+
+diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
+index 40e9d8e..e41fb74 100644
+--- a/drivers/mmc/host/dw_mmc.c
++++ b/drivers/mmc/host/dw_mmc.c
+@@ -99,6 +99,9 @@ struct idmac_desc {
+ 
+ 	__le32		des3;	/* buffer 2 physical address */
+ };
++
++/* Each descriptor can transfer up to 4KB of data in chained mode */
++#define DW_MCI_DESC_DATA_LENGTH	0x1000
+ #endif /* CONFIG_MMC_DW_IDMAC */
+ 
+ static bool dw_mci_reset(struct dw_mci *host);
+@@ -462,66 +465,96 @@ static void dw_mci_idmac_complete_dma(struct dw_mci *host)
+ static void dw_mci_translate_sglist(struct dw_mci *host, struct mmc_data *data,
+ 				    unsigned int sg_len)
+ {
++	unsigned int desc_len;
+ 	int i;
+ 	if (host->dma_64bit_address == 1) {
+-		struct idmac_desc_64addr *desc = host->sg_cpu;
++		struct idmac_desc_64addr *desc_first, *desc_last, *desc;
++
++		desc_first = desc_last = desc = host->sg_cpu;
+ 
+-		for (i = 0; i < sg_len; i++, desc++) {
++		for (i = 0; i < sg_len; i++) {
+ 			unsigned int length = sg_dma_len(&data->sg[i]);
+ 			u64 mem_addr = sg_dma_address(&data->sg[i]);
+ 
+-			/*
+-			 * Set the OWN bit and disable interrupts for this
+-			 * descriptor
+-			 */
+-			desc->des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC |
+-						IDMAC_DES0_CH;
+-			/* Buffer length */
+-			IDMAC_64ADDR_SET_BUFFER1_SIZE(desc, length);
+-
+-			/* Physical address to DMA to/from */
+-			desc->des4 = mem_addr & 0xffffffff;
+-			desc->des5 = mem_addr >> 32;
++			for ( ; length ; desc++) {
++				desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
++					   length : DW_MCI_DESC_DATA_LENGTH;
++
++				length -= desc_len;
++
++				/*
++				 * Set the OWN bit and disable interrupts
++				 * for this descriptor
++				 */
++				desc->des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC |
++							IDMAC_DES0_CH;
++
++				/* Buffer length */
++				IDMAC_64ADDR_SET_BUFFER1_SIZE(desc, desc_len);
++
++				/* Physical address to DMA to/from */
++				desc->des4 = mem_addr & 0xffffffff;
++				desc->des5 = mem_addr >> 32;
++
++				/* Update physical address for the next desc */
++				mem_addr += desc_len;
++
++				/* Save pointer to the last descriptor */
++				desc_last = desc;
++			}
+ 		}
+ 
+ 		/* Set first descriptor */
+-		desc = host->sg_cpu;
+-		desc->des0 |= IDMAC_DES0_FD;
++		desc_first->des0 |= IDMAC_DES0_FD;
+ 
+ 		/* Set last descriptor */
+-		desc = host->sg_cpu + (i - 1) *
+-				sizeof(struct idmac_desc_64addr);
+-		desc->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
+-		desc->des0 |= IDMAC_DES0_LD;
++		desc_last->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
++		desc_last->des0 |= IDMAC_DES0_LD;
+ 
+ 	} else {
+-		struct idmac_desc *desc = host->sg_cpu;
++		struct idmac_desc *desc_first, *desc_last, *desc;
++
++		desc_first = desc_last = desc = host->sg_cpu;
+ 
+-		for (i = 0; i < sg_len; i++, desc++) {
++		for (i = 0; i < sg_len; i++) {
+ 			unsigned int length = sg_dma_len(&data->sg[i]);
+ 			u32 mem_addr = sg_dma_address(&data->sg[i]);
+ 
+-			/*
+-			 * Set the OWN bit and disable interrupts for this
+-			 * descriptor
+-			 */
+-			desc->des0 = cpu_to_le32(IDMAC_DES0_OWN |
+-					IDMAC_DES0_DIC | IDMAC_DES0_CH);
+-			/* Buffer length */
+-			IDMAC_SET_BUFFER1_SIZE(desc, length);
++			for ( ; length ; desc++) {
++				desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
++					   length : DW_MCI_DESC_DATA_LENGTH;
++
++				length -= desc_len;
++
++				/*
++				 * Set the OWN bit and disable interrupts
++				 * for this descriptor
++				 */
++				desc->des0 = cpu_to_le32(IDMAC_DES0_OWN |
++							 IDMAC_DES0_DIC |
++							 IDMAC_DES0_CH);
++
++				/* Buffer length */
++				IDMAC_SET_BUFFER1_SIZE(desc, desc_len);
+ 
+-			/* Physical address to DMA to/from */
+-			desc->des2 = cpu_to_le32(mem_addr);
++				/* Physical address to DMA to/from */
++				desc->des2 = cpu_to_le32(mem_addr);
++
++				/* Update physical address for the next desc */
++				mem_addr += desc_len;
++
++				/* Save pointer to the last descriptor */
++				desc_last = desc;
++			}
+ 		}
+ 
+ 		/* Set first descriptor */
+-		desc = host->sg_cpu;
+-		desc->des0 |= cpu_to_le32(IDMAC_DES0_FD);
++		desc_first->des0 |= cpu_to_le32(IDMAC_DES0_FD);
+ 
+ 		/* Set last descriptor */
+-		desc = host->sg_cpu + (i - 1) * sizeof(struct idmac_desc);
+-		desc->des0 &= cpu_to_le32(~(IDMAC_DES0_CH | IDMAC_DES0_DIC));
+-		desc->des0 |= cpu_to_le32(IDMAC_DES0_LD);
++		desc_last->des0 &= cpu_to_le32(~(IDMAC_DES0_CH |
++					       IDMAC_DES0_DIC));
++		desc_last->des0 |= cpu_to_le32(IDMAC_DES0_LD);
+ 	}
+ 
+ 	wmb();
+@@ -2394,7 +2427,7 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
+ #ifdef CONFIG_MMC_DW_IDMAC
+ 		mmc->max_segs = host->ring_size;
+ 		mmc->max_blk_size = 65536;
+-		mmc->max_seg_size = 0x1000;
++		mmc->max_seg_size = DW_MCI_DESC_DATA_LENGTH;
+ 		mmc->max_req_size = mmc->max_seg_size * host->ring_size;
+ 		mmc->max_blk_count = mmc->max_req_size / 512;
+ #else
+-- 
+2.4.3
+