[PATCH v4 2/3] scsi: ufs: override auto suspend tunables for ufs

[Stanley Chu]

Rework from previous work by:
Sujit Reddy Thumma <sthu...@codeaurora.org>

Override auto suspend tunables for UFS device LUNs during
initialization so as to efficiently manage background operations
and the power consumption.

Signed-off-by: Stanley Chu <stanley....@mediatek.com>
Reviewed-by: Avri Altman <avri.alt...@wdc.com>
Reviewed-by: Bean Huo <bean...@micron.com>
---
 drivers/scsi/ufs/ufshcd.c |  9 +++++++++
 drivers/scsi/ufs/ufshcd.h | 10 ++++++++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 30b752c61b97..60a24fe908e7 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -88,6 +88,9 @@
 /* Interrupt aggregation default timeout, unit: 40us */
 #define INT_AGGR_DEF_TO        0x02
 
+/* default delay of autosuspend: 2000 ms */
+#define RPM_AUTOSUSPEND_DELAY_MS 2000
+
 #define ufshcd_toggle_vreg(_dev, _vreg, _on)                           \
        ({                                                              \
                int _ret;                                               \
@@ -4612,9 +4615,14 @@ static int ufshcd_change_queue_depth(struct scsi_device 
*sdev, int depth)
  */
 static int ufshcd_slave_configure(struct scsi_device *sdev)
 {
+       struct ufs_hba *hba = shost_priv(sdev->host);
        struct request_queue *q = sdev->request_queue;
 
        blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
+
+       if (ufshcd_is_rpm_autosuspend_allowed(hba))
+               sdev->rpm_autosuspend = 1;
+
        return 0;
 }
 
@@ -7041,6 +7049,7 @@ static struct scsi_host_template ufshcd_driver_template = 
{
        .track_queue_depth      = 1,
        .sdev_groups            = ufshcd_driver_groups,
        .dma_boundary           = PAGE_SIZE - 1,
+       .rpm_autosuspend_delay  = RPM_AUTOSUSPEND_DELAY_MS,
 };
 
 static int ufshcd_config_vreg_load(struct device *dev, struct ufs_vreg *vreg,
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index a43c7135f33d..99ea416519af 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -714,6 +714,12 @@ struct ufs_hba {
         * the performance of ongoing read/write operations.
         */
 #define UFSHCD_CAP_KEEP_AUTO_BKOPS_ENABLED_EXCEPT_SUSPEND (1 << 5)
+       /*
+        * This capability allows host controller driver to automatically
+        * enable runtime power management by itself instead of waiting
+        * for userspace to control the power management.
+        */
+#define UFSHCD_CAP_RPM_AUTOSUSPEND (1 << 6)
 
        struct devfreq *devfreq;
        struct ufs_clk_scaling clk_scaling;
@@ -747,6 +753,10 @@ static inline bool 
ufshcd_can_autobkops_during_suspend(struct ufs_hba *hba)
 {
        return hba->caps & UFSHCD_CAP_AUTO_BKOPS_SUSPEND;
 }
+static inline bool ufshcd_is_rpm_autosuspend_allowed(struct ufs_hba *hba)
+{
+       return hba->caps & UFSHCD_CAP_RPM_AUTOSUSPEND;
+}
 
 static inline bool ufshcd_is_intr_aggr_allowed(struct ufs_hba *hba)
 {
-- 
2.18.0