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

[Can Guo]

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 <c...@codeaurora.org>
---
 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;
-- 
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