[PATCH 4.9 21/72] scsi: ufs: add capability to keep auto bkops always enabled

From: Greg Kroah-Hartman
Date: Sun Nov 19 2017 - 10:08:44 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: "subhashj@xxxxxxxxxxxxxx" <subhashj@xxxxxxxxxxxxxx>


[ Upstream commit 4e768e7645ec4ffa92ee163643777b261ae97142 ]

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>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 33 ++++++++++++++++++++++-----------
drivers/scsi/ufs/ufshcd.h | 13 +++++++++++++
2 files changed, 35 insertions(+), 11 deletions(-)

--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3781,18 +3781,25 @@ out:
}

/**
- * 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)
@@ -6138,11 +6145,15 @@ static int ufshcd_resume(struct ufs_hba
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 (ufshcd_is_clkscaling_enabled(hba))
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -548,6 +548,14 @@ 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;
@@ -645,6 +653,11 @@ static inline void *ufshcd_get_variant(s
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);