u8500-shrm: Initiate MSR in case of serious bug

During APE-Modem communication, for some reasson if software or hardware
fails, instead of calling kernel function BUG() and halting the system
making it no more useful until reboot, initiate a MSR.

ST-Ericsson Linux next: NA
ST-Ericsson ID: 366150
ST-Ericsson FOSS-OUT ID: Trivial

Change-Id: I59e93b338c3242b506be7775487be065421022b8
Signed-off-by: Arun Murthy <arun.murthy@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/33416
Reviewed-by: Bibek BASU <bibek.basu@stericsson.com>
Reviewed-by: QABUILD
Reviewed-by: Magnus TEMPLING <magnus.templing@stericsson.com>
Reviewed-by: Rickard EVERTSSON <rickard.evertsson@stericsson.com>
Reviewed-by: Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com>

3 files changed, 35 insertions, 10 deletions

diff --git a/drivers/modem/shrm/shrm_fifo.c b/drivers/modem/shrm/shrm_fifo.c
index 1f0f9202e51..57da56f4905 100644
--- a/drivers/modem/shrm/shrm_fifo.c
+++ b/drivers/modem/shrm/shrm_fifo.c
@@ -11,6 +11,7 @@
 #include <linux/modem/shrm/shrm_driver.h>
 #include <linux/modem/shrm/shrm_private.h>
 #include <linux/modem/shrm/shrm_net.h>
+#include <linux/mfd/dbx500-prcmu.h>
 
 #define L1_BOOT_INFO_REQ	1
 #define L1_BOOT_INFO_RESP	2
@@ -109,7 +110,10 @@ u8 read_boot_info_req(struct shrm_dev *shrm,
 	if (msgtype != L1_BOOT_INFO_REQ) {
 		dev_err(shrm->dev, "Read_Boot_Info_Req Fatal ERROR\n");
 		dev_err(shrm->dev, "Received msgtype is %d\n", msgtype);
-		BUG();
+		dev_info(shrm->dev, "Initiating a modem reset\n");
+		queue_work(shrm->shm_ac_wake_wq,
+				&shrm->shm_mod_reset_req);
+		return 0;
 	}
 	*config = (header >> CONFIG_OFFSET) & MASK_0_15_BIT;
 	*version = header & MASK_0_15_BIT;
@@ -416,7 +420,9 @@ u8 read_one_l2msg_common(struct shrm_dev *shrm,
 						fifo->end_addr_fifo);
 		/* Fatal ERROR - should never happens */
 		dev_crit(shrm->dev, "Fatal ERROR - should never happen\n");
-		BUG();
+		dev_info(shrm->dev, "Initiating a modem reset\n");
+		queue_work(shrm->shm_ac_wake_wq,
+				&shrm->shm_mod_reset_req);
 	 }
 	if (fifo->reader_local_rptr == (fifo->end_addr_fifo-1)) {
 		l2_header = (*((u32 *)fifo->fifo_virtual_addr));
@@ -522,7 +528,9 @@ u8 read_one_l2msg_audio(struct shrm_dev *shrm,
 		dev_info(shrm->dev, "Received msgtype is %d\n", msgtype);
 		/* Fatal ERROR - should never happens */
 		dev_crit(shrm->dev, "Fatal ERROR - should never happen\n");
-		BUG();
+		dev_info(shrm->dev, "Initiating a modem reset\n");
+		queue_work(shrm->shm_ac_wake_wq,
+				&shrm->shm_mod_reset_req);
 	 }
 	if (fifo->reader_local_rptr == (fifo->end_addr_fifo-1)) {
 		l2_header = (*((u32 *)fifo->fifo_virtual_addr));
diff --git a/drivers/modem/shrm/shrm_protocol.c b/drivers/modem/shrm/shrm_protocol.c
index 50443e4803a..e34a88676be 100644
--- a/drivers/modem/shrm/shrm_protocol.c
+++ b/drivers/modem/shrm/shrm_protocol.c
@@ -70,6 +70,11 @@ enum shrm_nl {
 	SHRM_NL_STATUS_MOD_OFFLINE,
 };
 
+void shm_mod_reset_req_work(struct work_struct *work)
+{
+	prcmu_modem_reset();
+}
+
 static void shm_ac_sleep_req_work(struct work_struct *work)
 {
 	mutex_lock(&ac_state_mutex);
@@ -264,7 +269,7 @@ void shm_ca_msgpending_0_tasklet(unsigned long tasklet_data)
 			if (!read_boot_info_req(shrm, &config, &version)) {
 				dev_err(shrm->dev,
 						"Unable to read boot state\n");
-				BUG();
+				return;
 			}
 			/* SendReadNotification */
 			ca_msg_read_notification_0(shrm);
@@ -468,8 +473,11 @@ void shm_ca_wake_req_work(struct work_struct *work)
 	mutex_unlock(&ac_state_mutex);
 
 	/* send ca_wake_ack_interrupt to CMU */
-	if (!get_host_accessport_val())
-		BUG();
+	if (!get_host_accessport_val()) {
+		dev_crit(shrm->dev, "get_host_accessport failed\n");
+		dev_info(shrm->dev, "Initiating a modem reset\n");
+		prcmu_modem_reset();
+	}
 	writel((1<<GOP_CA_WAKE_ACK_BIT),
 			shm_dev->intr_base + GOP_SET_REGISTER_BASE);
 }
@@ -611,8 +619,11 @@ static void send_ac_msg_pend_notify_0_work(struct work_struct *work)
 	modem_request(shrm->modem);
 	mutex_unlock(&ac_state_mutex);
 
-	if (!get_host_accessport_val())
-		BUG();
+	if (!get_host_accessport_val()) {
+		dev_crit(shrm->dev, "get_host_accessport failed\n");
+		dev_info(shrm->dev, "Initiating a modem reset\n");
+		prcmu_modem_reset();
+	}
 
 	/* Trigger AcMsgPendingNotification to CMU */
 	writel((1<<GOP_COMMON_AC_MSG_PENDING_NOTIFICATION_BIT),
@@ -638,8 +649,11 @@ static void send_ac_msg_pend_notify_1_work(struct work_struct *work)
 	modem_request(shrm->modem);
 	mutex_unlock(&ac_state_mutex);
 
-	if (!get_host_accessport_val())
-		BUG();
+	if (!get_host_accessport_val()) {
+		dev_crit(shrm->dev, "get_host_accessport failed\n");
+		dev_info(shrm->dev, "Initiating a modem reset\n");
+		prcmu_modem_reset();
+	}
 
 	/* Trigger AcMsgPendingNotification to CMU */
 	writel((1<<GOP_AUDIO_AC_MSG_PENDING_NOTIFICATION_BIT),
@@ -734,6 +748,7 @@ int shrm_protocol_init(struct shrm_dev *shrm,
 	INIT_WORK(&shrm->shm_ca_sleep_req, shm_ca_sleep_req_work);
 	INIT_WORK(&shrm->shm_ac_sleep_req, shm_ac_sleep_req_work);
 	INIT_WORK(&shrm->shm_ac_wake_req, shm_ac_wake_req_work);
+	INIT_WORK(&shrm->shm_mod_reset_req, shm_mod_reset_req_work);
 
 	/* set tasklet data */
 	shm_ca_0_tasklet.data = (unsigned long)shrm;
diff --git a/include/linux/modem/shrm/shrm_driver.h b/include/linux/modem/shrm/shrm_driver.h
index e7b87005565..8fa215571eb 100644
--- a/include/linux/modem/shrm/shrm_driver.h
+++ b/include/linux/modem/shrm/shrm_driver.h
@@ -77,6 +77,7 @@
  * @shm_ca_wake_req:		work to send cmt-ape wake request
  * @shm_ca_sleep_req:		work to send cmt-ape sleep request
  * @shm_ac_sleep_req:		work to send ape-cmt sleep request
+ * @shm_mod_reset_req:		work to send a reset request to modem
  */
 struct shrm_dev {
 	u8 ca_wake_irq;
@@ -127,6 +128,7 @@ struct shrm_dev {
 	struct work_struct shm_ca_wake_req;
 	struct work_struct shm_ca_sleep_req;
 	struct work_struct shm_ac_sleep_req;
+	struct work_struct shm_mod_reset_req;
 };
 
 /**