[PATCH v1 08/12] scsi: ufs: add capability to keep auto bkops always enabled

From: Subhash Jadavani
Date: Mon Dec 12 2016 - 19:54:57 EST


UFS device requires to perform bkops (back ground operations) periodically
but host can control (via auto-bkops parameter of device) when device can
perform bkops based on its performance requirements. In general, host
would like to enable the device's auto-bkops only when it's not doing any
regular data transfer but sometimes device may not behave properly if host
keeps the auto-bkops disabled. This change adds the capability to let the
device auto-bkops always enabled except suspend.

Reviewed-by: Sahitya Tummala <stummala@xxxxxxxxxxxxxx>
Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 33 ++++++++++++++++++++++-----------
drivers/scsi/ufs/ufshcd.h | 13 +++++++++++++
2 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 43f9b44..53755d3 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4161,18 +4161,25 @@ static int ufshcd_disable_auto_bkops(struct ufs_hba *hba)
}

/**
- * ufshcd_force_reset_auto_bkops - force enable of auto bkops
+ * ufshcd_force_reset_auto_bkops - force reset auto bkops state
* @hba: per adapter instance
*
* After a device reset the device may toggle the BKOPS_EN flag
* to default value. The s/w tracking variables should be updated
- * as well. Do this by forcing enable of auto bkops.
+ * as well. This function would change the auto-bkops state based on
+ * UFSHCD_CAP_KEEP_AUTO_BKOPS_ENABLED_EXCEPT_SUSPEND.
*/
-static void ufshcd_force_reset_auto_bkops(struct ufs_hba *hba)
+static void ufshcd_force_reset_auto_bkops(struct ufs_hba *hba)
{
- hba->auto_bkops_enabled = false;
- hba->ee_ctrl_mask |= MASK_EE_URGENT_BKOPS;
- ufshcd_enable_auto_bkops(hba);
+ if (ufshcd_keep_autobkops_enabled_except_suspend(hba)) {
+ hba->auto_bkops_enabled = false;
+ hba->ee_ctrl_mask |= MASK_EE_URGENT_BKOPS;
+ ufshcd_enable_auto_bkops(hba);
+ } else {
+ hba->auto_bkops_enabled = true;
+ hba->ee_ctrl_mask &= ~MASK_EE_URGENT_BKOPS;
+ ufshcd_disable_auto_bkops(hba);
+ }
}

static inline int ufshcd_get_bkops_status(struct ufs_hba *hba, u32 *status)
@@ -6594,11 +6601,15 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
goto set_old_link_state;
}

- /*
- * If BKOPs operations are urgently needed at this moment then
- * keep auto-bkops enabled or else disable it.
- */
- ufshcd_urgent_bkops(hba);
+ if (ufshcd_keep_autobkops_enabled_except_suspend(hba))
+ ufshcd_enable_auto_bkops(hba);
+ else
+ /*
+ * If BKOPs operations are urgently needed at this moment then
+ * keep auto-bkops enabled or else disable it.
+ */
+ ufshcd_urgent_bkops(hba);
+
hba->clk_gating.is_suspended = false;

if (hba->clk_scaling.is_allowed)
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 97fbe4a..05d2055 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -566,6 +566,14 @@ struct ufs_hba {
* CAUTION: Enabling this might reduce overall UFS throughput.
*/
#define UFSHCD_CAP_INTR_AGGR (1 << 4)
+ /*
+ * This capability allows the device auto-bkops to be always enabled
+ * except during suspend (both runtime and suspend).
+ * Enabling this capability means that device will always be allowed
+ * to do background operation when it's active but it might degrade
+ * the performance of ongoing read/write operations.
+ */
+#define UFSHCD_CAP_KEEP_AUTO_BKOPS_ENABLED_EXCEPT_SUSPEND (1 << 5)

struct devfreq *devfreq;
struct ufs_clk_scaling clk_scaling;
@@ -663,6 +671,11 @@ static inline void *ufshcd_get_variant(struct ufs_hba *hba)
BUG_ON(!hba);
return hba->priv;
}
+static inline bool ufshcd_keep_autobkops_enabled_except_suspend(
+ struct ufs_hba *hba)
+{
+ return hba->caps & UFSHCD_CAP_KEEP_AUTO_BKOPS_ENABLED_EXCEPT_SUSPEND;
+}

extern int ufshcd_runtime_suspend(struct ufs_hba *hba);
extern int ufshcd_runtime_resume(struct ufs_hba *hba);
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project