[PATCH v1 2/3] scsi: ufs: override auto suspend tunables for ufs

[Stanley Chu <stanley.chu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>]

Rework from previous work by:
Sujit Reddy Thumma <sthumma-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.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.chu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
 drivers/scsi/ufs/ufshcd.c |  8 ++++++++
 drivers/scsi/ufs/ufshcd.h | 10 ++++++++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 30b752c61b97..d253a018a73b 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_delay = RPM_AUTOSUSPEND_DELAY_MS;
+
 	return 0;
 }
 
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