| Message ID | 20201026195124.363096-6-jaegeuk@kernel.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v4,1/5] scsi: ufs: atomic update for clkgating_enable | expand |
On 2020-10-27 03:51, Jaegeuk Kim wrote: > 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. > > Fixes: 7252a3603015 ("scsi: ufs: Avoid busy-waiting by eliminating tag > conflicts") > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> > Reviewed-by: Asutosh Das <asutoshd@codeaurora.org> Reviewed-by: Can Guo <cang@codeaurora.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 b8a54d09e750..86c8dee01ca9 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -1746,7 +1746,7 @@ 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;
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index b8a54d09e750..86c8dee01ca9 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1746,7 +1746,7 @@ 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;
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. Fixes: 7252a3603015 ("scsi: ufs: Avoid busy-waiting by eliminating tag conflicts") Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Reviewed-by: Asutosh Das <asutoshd@codeaurora.org> --- drivers/scsi/ufs/ufshcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)