[PATCH v1 1/2] scsi: ufs: core: Support Updating UIC Command Timeout

[Bao D. Nguyen]

The default UIC command timeout still remains 500ms.
Allow vendor drivers to override the UIC command timeout if desired.

In a real product, the 500ms timeout value is probably good enough.
However, during the product development where there are a lot of
logging and debug messages being printed to the uart console,
interrupt starvations happen occasionally because the uart may
print long debug messages from different modules in the system.
While printing, the uart may have interrupts disabled for more
than 500ms, causing UIC command timeout.
The UIC command timeout would trigger more printing from the
UFS driver, and eventually a watchdog timeout may occur unnecessarily.

Signed-off-by: Bao D. Nguyen <quic_nguyenb@xxxxxxxxxxx>
---
 drivers/ufs/core/ufshcd.c | 9 ++++++---
 include/ufs/ufshcd.h      | 2 ++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 21429ee..c440caf 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2460,7 +2460,7 @@ static inline bool ufshcd_ready_for_uic_cmd(struct ufs_hba *hba)
 {
 	u32 val;
 	int ret = read_poll_timeout(ufshcd_readl, val, val & UIC_COMMAND_READY,
-				    500, UIC_CMD_TIMEOUT * 1000, false, hba,
+				    500, hba->uic_cmd_timeout * 1000, false, hba,
 				    REG_CONTROLLER_STATUS);
 	return ret == 0;
 }
@@ -2520,7 +2520,7 @@ ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
 	lockdep_assert_held(&hba->uic_cmd_mutex);
 
 	if (wait_for_completion_timeout(&uic_cmd->done,
-					msecs_to_jiffies(UIC_CMD_TIMEOUT))) {
+					msecs_to_jiffies(hba->uic_cmd_timeout))) {
 		ret = uic_cmd->argument2 & MASK_UIC_COMMAND_RESULT;
 	} else {
 		ret = -ETIMEDOUT;
@@ -4298,7 +4298,7 @@ static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba, struct uic_command *cmd)
 	}
 
 	if (!wait_for_completion_timeout(hba->uic_async_done,
-					 msecs_to_jiffies(UIC_CMD_TIMEOUT))) {
+					 msecs_to_jiffies(hba->uic_cmd_timeout))) {
 		dev_err(hba->dev,
 			"pwr ctrl cmd 0x%x with mode 0x%x completion timeout\n",
 			cmd->command, cmd->argument3);
@@ -10690,6 +10690,9 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 			    FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
 	}
 
+	if (!hba->uic_cmd_timeout)
+		hba->uic_cmd_timeout = UIC_CMD_TIMEOUT;
+
 	/* Hold auto suspend until async scan completes */
 	pm_runtime_get_sync(dev);
 	atomic_set(&hba->scsi_block_reqs_cnt, 0);
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index a35e12f..47e3bdf 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -917,6 +917,7 @@ enum ufshcd_mcq_opr {
  * @ufs_rtc_update_work: A work for UFS RTC periodic update
  * @pm_qos_req: PM QoS request handle
  * @pm_qos_enabled: flag to check if pm qos is enabled
+ * @uic_cmd_timeout: timeout in ms for UIC commands
  */
 struct ufs_hba {
 	void __iomem *mmio_base;
@@ -1085,6 +1086,7 @@ struct ufs_hba {
 	struct delayed_work ufs_rtc_update_work;
 	struct pm_qos_request pm_qos_req;
 	bool pm_qos_enabled;
+	u32 uic_cmd_timeout;
 };
 
 /**
-- 
2.7.4