From 66692a44e7df8b9f4b4e0e92e2f324e7856b34fe Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Thu, 15 Oct 2020 22:57:41 -0700 Subject: [PATCH] FROMLIST: scsi: ufs: fix clkgating on/off correctly The below call stack prevents clk_gating at every IO completion. We can remove the condition, ufshcd_any_tag_in_use(), since clkgating_work will check it again. ufshcd_complete_requests(struct ufs_hba *hba) ufshcd_transfer_req_compl() __ufshcd_transfer_req_compl() __ufshcd_release(hba) if (ufshcd_any_tag_in_use() == 1) return; ufshcd_tmc_handler(hba); blk_mq_tagset_busy_iter(); Note that, this still requires a work to deal with a potential racy condition when user sets clkgating.delay_ms to very small value. That can cause preventing clkgating by the check of ufshcd_any_tag_in_use() in gate_work. Link: https://lore.kernel.org/linux-scsi/20201028194352.GA3060274@google.com/T/#m3485ba8df14e4ad5cf0aa5b314ffe1cb90d90105 Fixes: 7252a3603015 ("scsi: ufs: Avoid busy-waiting by eliminating tag conflicts") Signed-off-by: Jaegeuk Kim Reviewed-by: Asutosh Das Change-Id: I9b56725b26e1be8b1da55ae1db7322ab00fc5298 --- drivers/scsi/ufs/ufshcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index f33d25d53a1b..ed68d4dab0a8 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1745,7 +1745,7 @@ static void __ufshcd_release(struct ufs_hba *hba) if (hba->clk_gating.active_reqs || hba->clk_gating.is_suspended || hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL || - ufshcd_any_tag_in_use(hba) || hba->outstanding_tasks || + hba->outstanding_tasks || hba->active_uic_cmd || hba->uic_async_done || hba->clk_gating.state == CLKS_OFF) return;