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[v5,1/1] scsi: ufs: core: Support Updating UIC Command Timeout

Message ID e4e1c87f3f867f270a3d4b5d57a00139ff0e9741.1721792309.git.quic_nguyenb@quicinc.com
State New
Headers show
Series Allow platform drivers to update UIC command timeout | expand

Commit Message

Bao D. Nguyen July 24, 2024, 3:49 a.m. UTC 
The default UIC command timeout still remains 500ms.
Allow platform 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.

Add support for overriding the UIC command timeout value
with the newly created uic_cmd_timeout kernel module parameter.
Default value is 500ms. Supported values range from 500ms
to 2 seconds.

Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/ufs/core/ufshcd.c | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

Comments

Martin K. Petersen Aug. 3, 2024, 1:42 a.m. UTC | #1 
Bao,

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

Applied to 6.12/scsi-staging, thanks!
diff mbox series

Patch

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 21429ee..526d542 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -51,8 +51,10 @@ 
 
 
 /* UIC command timeout, unit: ms */
-#define UIC_CMD_TIMEOUT	500
-
+enum {
+	UIC_CMD_TIMEOUT_DEFAULT	= 500,
+	UIC_CMD_TIMEOUT_MAX	= 2000,
+};
 /* NOP OUT retries waiting for NOP IN response */
 #define NOP_OUT_RETRIES    10
 /* Timeout after 50 msecs if NOP OUT hangs without response */
@@ -113,6 +115,23 @@  static bool is_mcq_supported(struct ufs_hba *hba)
 module_param(use_mcq_mode, bool, 0644);
 MODULE_PARM_DESC(use_mcq_mode, "Control MCQ mode for controllers starting from UFSHCI 4.0. 1 - enable MCQ, 0 - disable MCQ. MCQ is enabled by default");
 
+static unsigned int uic_cmd_timeout = UIC_CMD_TIMEOUT_DEFAULT;
+
+static int uic_cmd_timeout_set(const char *val, const struct kernel_param *kp)
+{
+	return param_set_uint_minmax(val, kp, UIC_CMD_TIMEOUT_DEFAULT,
+				     UIC_CMD_TIMEOUT_MAX);
+}
+
+static const struct kernel_param_ops uic_cmd_timeout_ops = {
+	.set = uic_cmd_timeout_set,
+	.get = param_get_uint,
+};
+
+module_param_cb(uic_cmd_timeout, &uic_cmd_timeout_ops, &uic_cmd_timeout, 0644);
+MODULE_PARM_DESC(uic_cmd_timeout,
+		 "UFS UIC command timeout in milliseconds. Defaults to 500ms. Supported values range from 500ms to 2 seconds inclusively");
+
 #define ufshcd_toggle_vreg(_dev, _vreg, _on)				\
 	({                                                              \
 		int _ret;                                               \
@@ -2460,7 +2479,7 @@  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, uic_cmd_timeout * 1000, false, hba,
 				    REG_CONTROLLER_STATUS);
 	return ret == 0;
 }
@@ -2520,7 +2539,7 @@  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(uic_cmd_timeout))) {
 		ret = uic_cmd->argument2 & MASK_UIC_COMMAND_RESULT;
 	} else {
 		ret = -ETIMEDOUT;
@@ -4298,7 +4317,7 @@  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(uic_cmd_timeout))) {
 		dev_err(hba->dev,
 			"pwr ctrl cmd 0x%x with mode 0x%x completion timeout\n",
 			cmd->command, cmd->argument3);