From: Jaegeuk Kim jaegeuk@google.com
[ Upstream commit b664511297644eac34038df877b3ad7bcaa81913 ]
While running a stress test which enables/disables clkgating, we occasionally hit device timeout. This patch avoids a subtle race condition to address it.
Link: https://lore.kernel.org/r/20201117165839.1643377-3-jaegeuk@kernel.org Reviewed-by: Can Guo cang@codeaurora.org Signed-off-by: Jaegeuk Kim jaegeuk@google.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/ufs/ufshcd.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 7e4e6e982055e..b2fd853f07573 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1766,19 +1766,19 @@ static ssize_t ufshcd_clkgate_enable_store(struct device *dev, return -EINVAL;
value = !!value; + + spin_lock_irqsave(hba->host->host_lock, flags); if (value == hba->clk_gating.is_enabled) goto out;
- if (value) { - ufshcd_release(hba); - } else { - spin_lock_irqsave(hba->host->host_lock, flags); + if (value) + __ufshcd_release(hba); + else hba->clk_gating.active_reqs++; - spin_unlock_irqrestore(hba->host->host_lock, flags); - }
hba->clk_gating.is_enabled = value; out: + spin_unlock_irqrestore(hba->host->host_lock, flags); return count; }