From: Jaegeuk Kim jaegeuk@kernel.org
[ Upstream commit 8eb456be75af7e5a7ac0cd223eaa198cf7ee2ac1 ]
The following call stack prevents clk_gating at every I/O 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 work to deal with a potential race 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/r/20201117165839.1643377-7-jaegeuk@kernel.org Fixes: 7252a3603015 ("scsi: ufs: Avoid busy-waiting by eliminating tag conflicts") Reviewed-by: Asutosh Das asutoshd@codeaurora.org Reviewed-by: Can Guo cang@codeaurora.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1ad7d6c130f5b..911aba3e7675c 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1751,7 +1751,7 @@ 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;