Re: [PATCH] scsi: ufs: Try to save power mode change and UIC cmd completion timeout

From: Can Guo
Date: Tue Nov 03 2020 - 08:29:08 EST


Sorry, please ignore this specific change, which is wrongly sent out.

On 2020-11-03 14:24, Can Guo wrote:
Use the uic_cmd->cmd_active as a flag to track the lifecycle of an UIC cmd.
The flag is set before send the UIC cmd and cleared after the completion is
raised in IRQ handler. For a power mode change operation, including hibern8
enter/exit, the flag is cleared only after hba->uic_async_done completion
is raised. When completion timeout happens, if the flag is cleared, instead
of returning timeout error, simply ignore it.

Change-Id: Ie3cd6ae6221a44619925fb2cf78136a5617fdd5d
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 252e022..8b291c3 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -2131,10 +2131,20 @@ ufshcd_wait_for_uic_cmd(struct ufs_hba *hba,
struct uic_command *uic_cmd)
unsigned long flags;

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
+ } else {
ret = -ETIMEDOUT;
+ dev_err(hba->dev,
+ "uic cmd 0x%x with arg3 0x%x completion timeout\n",
+ uic_cmd->command, uic_cmd->argument3);
+
+ if (!uic_cmd->cmd_active) {
+ dev_err(hba->dev, "%s: UIC cmd has been completed, return the result\n",
+ __func__);
+ ret = uic_cmd->argument2 & MASK_UIC_COMMAND_RESULT;
+ }
+ }

spin_lock_irqsave(hba->host->host_lock, flags);
hba->active_uic_cmd = NULL;
@@ -2166,6 +2176,7 @@ __ufshcd_send_uic_cmd(struct ufs_hba *hba,
struct uic_command *uic_cmd,
if (completion)
init_completion(&uic_cmd->done);

+ uic_cmd->cmd_active = 1;
ufshcd_dispatch_uic_cmd(hba, uic_cmd);

return 0;
@@ -3944,10 +3955,18 @@ static int ufshcd_uic_pwr_ctrl(struct ufs_hba
*hba, struct uic_command *cmd)
dev_err(hba->dev,
"pwr ctrl cmd 0x%x with mode 0x%x completion timeout\n",
cmd->command, cmd->argument3);
+
+ if (!cmd->cmd_active) {
+ dev_err(hba->dev, "%s: Power Mode Change operation has been
completed, go check UPMCRS\n",
+ __func__);
+ goto check_upmcrs;
+ }
+
ret = -ETIMEDOUT;
goto out;
}

+check_upmcrs:
status = ufshcd_get_upmcrs(hba);
if (status != PWR_LOCAL) {
dev_err(hba->dev,
@@ -5060,11 +5079,14 @@ static irqreturn_t ufshcd_uic_cmd_compl(struct
ufs_hba *hba, u32 intr_status)
hba->active_uic_cmd->argument3 =
ufshcd_get_dme_attr_val(hba);
complete(&hba->active_uic_cmd->done);
+ if (!hba->uic_async_done)
+ hba->active_uic_cmd->cmd_active = 0;
retval = IRQ_HANDLED;
}

if ((intr_status & UFSHCD_UIC_PWR_MASK) && hba->uic_async_done) {
complete(hba->uic_async_done);
+ hba->active_uic_cmd->cmd_active = 0;
retval = IRQ_HANDLED;
}
return retval;