[PATCH v2 0/2] skipping manual flush for write booster

[PATCH v2 0/2] skipping manual flush for write booster

[Kiwoong Kim]

v2 -> v1: enable the quirk in exynos

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

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 v2 1/2] ufs: introduce skipping manual flush for wb

[Kiwoong Kim]

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

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

RE: [PATCH v2 1/2] ufs: introduce skipping manual flush for wb

[Avri Altman]

 
> 
> We have two knobs to flush for write booster, i.e.
> fWriteBoosterEn, fWriteBoosterBufferFlushEn.
fWriteBoosterBufferFlushDuringHibernate and fWriteBoosterBufferFlushEn.

> However, many product makers uses only fWriteBoosterBufferFlushEn,
Uses only fWriteBoosterBufferFlushDuringHibernate

> because this can reportedly cover most scenarios and
> there have been some reports that flush by fWriteBoosterEn could
flush by fWriteBoosterBufferFlushEn could

> lead 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 v2 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>
---
 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 v2 2/2] ufs: exynos: enable UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL

[Avri Altman]

 
> 
> 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>

RE: [PATCH v2 0/2] skipping manual flush for write booster

[Avri Altman]

 
> 
> v2 -> v1: enable the quirk in exynos
> 
> We have two knobs to flush for write booster, i.e.
> fWriteBoosterEn, fWriteBoosterBufferFlushEn.
fWriteBoosterBufferFlushDuringHibernate and fWriteBoosterBufferFlushEn.

> However, many product makers uses only fWriteBoosterBufferFlushEn,
Uses only fWriteBoosterBufferFlushDuringHibernate
> because this can reportedly cover most scenarios and
> there have been some reports that flush by fWriteBoosterEn could
flush by fWriteBoosterBufferFlushEn could

> lead raise power consumption thanks to unexpected internal
lead to a raise

> operations. So we need a way to enable or disable fWriteBoosterEn.
operations. For those case, this quirk will allow to avoid manual flush.

RE: [PATCH v2 0/2] skipping manual flush for write booster

[Kiwoong Kim]

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

It was my mistake and I'll be more careful when writing messages.

Thanks.
Kiwoong Kim