From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> [ 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@xxxxxxxxxx Reviewed-by: Can Guo <cang@xxxxxxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 a3a3ee6e2a002..68d3d463e2e16 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1649,19 +1649,19 @@ 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; } -- 2.27.0
