[PATCH v3 0/2] ufs: introduce skipping manual flush for wb

[PATCH v3 0/2] ufs: introduce skipping manual flush for wb

[Kiwoong Kim]

v1 -> v2: enable the quirk in exynos
v2 -> v3: modify some commit messages

We have two knobs to flush for write booster, i.e.
fWriteBoosterBufferFlushDuringHibernate and fWriteBoosterBufferFlushEn.
However, many product makers uses only fWriteBoosterBufferFlushDuringHibernate,
because this can reportedly cover most scenarios and
there have been some reports that flush by fWriteBoosterBufferFlushEn
could lead to raise power consumption thanks to unexpected internal
operations. So we need a way to enable or disable fWriteBoosterEn
operations. For those case, this quirk will allow to avoid manual flush

Kiwoong Kim (2):
  ufs: introduce skipping manual flush for wb
  ufs: exynos: enable UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL

 drivers/scsi/ufs/ufs-exynos.c | 3 ++-
 drivers/scsi/ufs/ufshcd.c     | 3 +++
 drivers/scsi/ufs/ufshcd.h     | 5 +++++
 3 files changed, 10 insertions(+), 1 deletion(-)

-- 
2.7.4

[PATCH v3 1/2] ufs: introduce skipping manual flush for wb

[Kiwoong Kim]

We have two knobs to flush for write booster, i.e.
fWriteBoosterBufferFlushDuringHibernate and fWriteBoosterBufferFlushEn.
However, many product makers uses only fWriteBoosterBufferFlushDuringHibernate,
because this can reportedly cover most scenarios and
there have been some reports that flush by fWriteBoosterBufferFlushEn
could lead to raise power consumption thanks to unexpected internal
operations. So we need a way to enable or disable fWriteBoosterEn
operations. For those case, this quirk will allow to avoid manual flush

Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
---
 drivers/scsi/ufs/ufshcd.c | 3 +++
 drivers/scsi/ufs/ufshcd.h | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ed03051..7c79a8f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5277,6 +5277,9 @@ static int ufshcd_wb_toggle_flush_during_h8(struct ufs_hba *hba, bool set)
 
 static inline void ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool enable)
 {
+	if (hba->quirks & UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL)
+		return;
+
 	if (enable)
 		ufshcd_wb_buf_flush_enable(hba);
 	else
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index e5353d6..cfafd6e 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -511,6 +511,11 @@ enum ufshcd_quirks {
 	 * OCS FATAL ERROR with device error through sense data
 	 */
 	UFSHCD_QUIRK_BROKEN_OCS_FATAL_ERROR		= 1 << 10,
+
+	/*
+	 * This quirk needs to disable manual flush for write booster
+	 */
+	UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL		= 1 << 11,
 };
 
 enum ufshcd_caps {
-- 
2.7.4

[PATCH v3 2/2] ufs: exynos: enable UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL

[Kiwoong Kim]

For Exynos, only flush during hibern8 is enough for
sustaining performance and I think that there is
a possiblity of raising current thanks to an increase
of internal operations for manual flush.

Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
---
 drivers/scsi/ufs/ufs-exynos.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufs-exynos.c b/drivers/scsi/ufs/ufs-exynos.c
index 3c0a50b..defbcc2 100644
--- a/drivers/scsi/ufs/ufs-exynos.c
+++ b/drivers/scsi/ufs/ufs-exynos.c
@@ -1289,7 +1289,8 @@ struct exynos_ufs_drv_data exynos_ufs_drvs = {
 				  UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR |
 				  UFSHCI_QUIRK_BROKEN_HCE |
 				  UFSHCI_QUIRK_SKIP_RESET_INTR_AGGR |
-				  UFSHCD_QUIRK_BROKEN_OCS_FATAL_ERROR,
+				  UFSHCD_QUIRK_BROKEN_OCS_FATAL_ERROR |
+				  UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL,
 	.opts			= EXYNOS_UFS_OPT_HAS_APB_CLK_CTRL |
 				  EXYNOS_UFS_OPT_BROKEN_AUTO_CLK_CTRL |
 				  EXYNOS_UFS_OPT_BROKEN_RX_SEL_IDX |
-- 
2.7.4

RE: [PATCH v3 1/2] ufs: introduce skipping manual flush for wb

[Avri Altman]

 
> 
> We have two knobs to flush for write booster, i.e.
> fWriteBoosterBufferFlushDuringHibernate and fWriteBoosterBufferFlushEn.
> However, many product makers uses only
> fWriteBoosterBufferFlushDuringHibernate,
> because this can reportedly cover most scenarios and
> there have been some reports that flush by fWriteBoosterBufferFlushEn
> could lead to raise power consumption thanks to unexpected internal
> operations. So we need a way to enable or disable fWriteBoosterEn
> operations. For those case, this quirk will allow to avoid manual flush
> 
> Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>

Re: [PATCH v3 0/2] ufs: introduce skipping manual flush for wb

[Martin K. Petersen]

On Tue, 25 Aug 2020 10:43:14 +0900, Kiwoong Kim wrote:

> v1 -> v2: enable the quirk in exynos
> v2 -> v3: modify some commit messages
> 
> We have two knobs to flush for write booster, i.e.
> fWriteBoosterBufferFlushDuringHibernate and fWriteBoosterBufferFlushEn.
> However, many product makers uses only fWriteBoosterBufferFlushDuringHibernate,
> because this can reportedly cover most scenarios and
> there have been some reports that flush by fWriteBoosterBufferFlushEn
> could lead to raise power consumption thanks to unexpected internal
> operations. So we need a way to enable or disable fWriteBoosterEn
> operations. For those case, this quirk will allow to avoid manual flush
> 
> [...]

Applied to 5.10/scsi-queue, thanks!

[1/2] scsi: ufs: Introduce skipping manual flush for Write Booster
      https://git.kernel.org/mkp/scsi/c/5df6f2def50c
[2/2] scsi: ufs: exynos: Enable UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL
      https://git.kernel.org/mkp/scsi/c/7973b8ac669e

-- 
Martin K. Petersen	Oracle Linux Engineering