diff mbox

[v1,07/10] scsi: ufs: introduce UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE quirk

Message ID 1431878106-30579-8-git-send-email-ygardi@codeaurora.org (mailing list archive)
State Not Applicable, archived
Delegated to: Andy Gross
Headers show

Commit Message

Yaniv Gardi May 17, 2015, 3:55 p.m. UTC
Some UFS host controllers may only allow accessing the peer DME attribute
in AUTO mode (FAST AUTO or SLOW AUTO) hence we had added a quirk for
switching to AUTO power mode before accessing the peer DME attribute.

Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>

---
 drivers/scsi/ufs/ufshcd.c | 31 +++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.h |  7 +++++++
 2 files changed, 38 insertions(+)

Comments

Akinobu Mita May 19, 2015, 2:33 p.m. UTC | #1
2015-05-18 0:55 GMT+09:00 Yaniv Gardi <ygardi@codeaurora.org>:
> Some UFS host controllers may only allow accessing the peer DME attribute
> in AUTO mode (FAST AUTO or SLOW AUTO) hence we had added a quirk for
> switching to AUTO power mode before accessing the peer DME attribute.
>
> Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
>
> ---
>  drivers/scsi/ufs/ufshcd.c | 31 +++++++++++++++++++++++++++++++
>  drivers/scsi/ufs/ufshcd.h |  7 +++++++
>  2 files changed, 38 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index a274df9..014f1c0 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -188,6 +188,8 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba);
>  static irqreturn_t ufshcd_intr(int irq, void *__hba);
>  static int ufshcd_config_pwr_mode(struct ufs_hba *hba,
>                 struct ufs_pa_layer_attr *desired_pwr_mode);
> +static int ufshcd_change_power_mode(struct ufs_hba *hba,
> +                            struct ufs_pa_layer_attr *pwr_mode);
>
>  static inline int ufshcd_enable_irq(struct ufs_hba *hba)
>  {
> @@ -2156,6 +2158,31 @@ int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
>         };
>         const char *get = action[!!peer];
>         int ret;
> +       struct ufs_pa_layer_attr orig_pwr_info;
> +       struct ufs_pa_layer_attr temp_pwr_info;
> +       bool pwr_mode_change = false;
> +
> +       if (peer && (hba->quirks & UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE)) {
> +               orig_pwr_info = hba->pwr_info;
> +               temp_pwr_info = orig_pwr_info;
> +
> +               if (orig_pwr_info.pwr_tx == FAST_MODE ||
> +                   orig_pwr_info.pwr_rx == FAST_MODE) {
> +                       temp_pwr_info.pwr_tx = FASTAUTO_MODE;
> +                       temp_pwr_info.pwr_rx = FASTAUTO_MODE;
> +                       pwr_mode_change = true;
> +               } else if (orig_pwr_info.pwr_tx == SLOW_MODE ||
> +                   orig_pwr_info.pwr_rx == SLOW_MODE) {
> +                       temp_pwr_info.pwr_tx = SLOWAUTO_MODE;
> +                       temp_pwr_info.pwr_rx = SLOWAUTO_MODE;
> +                       pwr_mode_change = true;
> +               }

What happens if tx and rx have different power mode (although it is
strange setting) ?

For example, if the current power mode is pwr_tx=FAST_MODE, gear_tx=3
and pwr_rx=SLOW_MODE, gear_rx=4, the temporary power mode will be
pwr_tx=FASTAUTO_MODE, gear_tx=3 and pwr_rx=FASTAUTO_MODE, gear_rx=4.
But HS-G4 is invalid.

> +               if (pwr_mode_change) {
> +                       ret = ufshcd_change_power_mode(hba, &temp_pwr_info);
> +                       if (ret)
> +                               goto out;
> +               }
> +       }
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Akinobu Mita May 19, 2015, 3:21 p.m. UTC | #2
2015-05-18 0:55 GMT+09:00 Yaniv Gardi <ygardi@codeaurora.org>:
> Some UFS host controllers may only allow accessing the peer DME attribute
> in AUTO mode (FAST AUTO or SLOW AUTO) hence we had added a quirk for
> switching to AUTO power mode before accessing the peer DME attribute.
>
> Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
>
> ---
>  drivers/scsi/ufs/ufshcd.c | 31 +++++++++++++++++++++++++++++++
>  drivers/scsi/ufs/ufshcd.h |  7 +++++++
>  2 files changed, 38 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index a274df9..014f1c0 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -188,6 +188,8 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba);
>  static irqreturn_t ufshcd_intr(int irq, void *__hba);
>  static int ufshcd_config_pwr_mode(struct ufs_hba *hba,
>                 struct ufs_pa_layer_attr *desired_pwr_mode);
> +static int ufshcd_change_power_mode(struct ufs_hba *hba,
> +                            struct ufs_pa_layer_attr *pwr_mode);
>
>  static inline int ufshcd_enable_irq(struct ufs_hba *hba)
>  {
> @@ -2156,6 +2158,31 @@ int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
>         };
>         const char *get = action[!!peer];
>         int ret;
> +       struct ufs_pa_layer_attr orig_pwr_info;
> +       struct ufs_pa_layer_attr temp_pwr_info;
> +       bool pwr_mode_change = false;
> +
> +       if (peer && (hba->quirks & UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE)) {
> +               orig_pwr_info = hba->pwr_info;
> +               temp_pwr_info = orig_pwr_info;
> +
> +               if (orig_pwr_info.pwr_tx == FAST_MODE ||
> +                   orig_pwr_info.pwr_rx == FAST_MODE) {
> +                       temp_pwr_info.pwr_tx = FASTAUTO_MODE;
> +                       temp_pwr_info.pwr_rx = FASTAUTO_MODE;
> +                       pwr_mode_change = true;
> +               } else if (orig_pwr_info.pwr_tx == SLOW_MODE ||
> +                   orig_pwr_info.pwr_rx == SLOW_MODE) {
> +                       temp_pwr_info.pwr_tx = SLOWAUTO_MODE;
> +                       temp_pwr_info.pwr_rx = SLOWAUTO_MODE;
> +                       pwr_mode_change = true;
> +               }
> +               if (pwr_mode_change) {
> +                       ret = ufshcd_change_power_mode(hba, &temp_pwr_info);

I'm a bit worried that this could cause an infinite recursion if
someone adds ufshcd_dme_peer_get() in ufshcd_change_power_mode()
for debugging or investigation.

So isn't it better to add note in code comment, or detect infinite
recursion?
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diff mbox

Patch

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a274df9..014f1c0 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -188,6 +188,8 @@  static int ufshcd_host_reset_and_restore(struct ufs_hba *hba);
 static irqreturn_t ufshcd_intr(int irq, void *__hba);
 static int ufshcd_config_pwr_mode(struct ufs_hba *hba,
 		struct ufs_pa_layer_attr *desired_pwr_mode);
+static int ufshcd_change_power_mode(struct ufs_hba *hba,
+			     struct ufs_pa_layer_attr *pwr_mode);
 
 static inline int ufshcd_enable_irq(struct ufs_hba *hba)
 {
@@ -2156,6 +2158,31 @@  int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
 	};
 	const char *get = action[!!peer];
 	int ret;
+	struct ufs_pa_layer_attr orig_pwr_info;
+	struct ufs_pa_layer_attr temp_pwr_info;
+	bool pwr_mode_change = false;
+
+	if (peer && (hba->quirks & UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE)) {
+		orig_pwr_info = hba->pwr_info;
+		temp_pwr_info = orig_pwr_info;
+
+		if (orig_pwr_info.pwr_tx == FAST_MODE ||
+		    orig_pwr_info.pwr_rx == FAST_MODE) {
+			temp_pwr_info.pwr_tx = FASTAUTO_MODE;
+			temp_pwr_info.pwr_rx = FASTAUTO_MODE;
+			pwr_mode_change = true;
+		} else if (orig_pwr_info.pwr_tx == SLOW_MODE ||
+		    orig_pwr_info.pwr_rx == SLOW_MODE) {
+			temp_pwr_info.pwr_tx = SLOWAUTO_MODE;
+			temp_pwr_info.pwr_rx = SLOWAUTO_MODE;
+			pwr_mode_change = true;
+		}
+		if (pwr_mode_change) {
+			ret = ufshcd_change_power_mode(hba, &temp_pwr_info);
+			if (ret)
+				goto out;
+		}
+	}
 
 	uic_cmd.command = peer ?
 		UIC_CMD_DME_PEER_GET : UIC_CMD_DME_GET;
@@ -2170,6 +2197,10 @@  int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
 
 	if (mib_val)
 		*mib_val = uic_cmd.argument3;
+
+	if (peer && (hba->quirks & UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE)
+	    && pwr_mode_change)
+		ufshcd_change_power_mode(hba, &orig_pwr_info);
 out:
 	return ret;
 }
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 8636ec9..eb6831d 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -442,6 +442,13 @@  struct ufs_hba {
 	 */
 	#define UFSHCD_QUIRK_BROKEN_PA_RXHSUNTERMCAP		UFS_BIT(3)
 
+	/*
+	 * This quirk needs to be enabled if the host contoller only allows
+	 * accessing the peer dme attributes in AUTO mode (FAST AUTO or
+	 * SLOW AUTO).
+	 */
+	#define UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE		UFS_BIT(4)
+
 	unsigned int quirks;	/* Deviations from standard UFSHCI spec. */
 
 	wait_queue_head_t tm_wq;