After enter hibern8, as UFS JEDEC ver 3.0 requires, a specific gating wait
time is required before disable the device reference clock. If it is not
specified, use the old delay.
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
Reviewed-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
Reviewed-by: Hongwu Su <hongwus@xxxxxxxxxxxxxx>
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 85d7c17..39eefa4 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -833,6 +833,8 @@ static int ufs_qcom_bus_register(struct ufs_qcom_host *host)
static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
{
+ unsigned long gating_wait;
+
if (host->dev_ref_clk_ctrl_mmio &&
(enable ^ host->is_dev_ref_clk_enabled)) {
u32 temp = readl_relaxed(host->dev_ref_clk_ctrl_mmio);
@@ -845,11 +847,25 @@ static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
/*
* If we are here to disable this clock it might be immediately
* after entering into hibern8 in which case we need to make
- * sure that device ref_clk is active at least 1us after the
+ * sure that device ref_clk is active for specific time after
* hibern8 enter.
*/
- if (!enable)
- udelay(1);
+ if (!enable) {
+ gating_wait = host->hba->dev_info.clk_gating_wait_us;
+ if (!gating_wait) {
+ udelay(1);
+ } else {
+ /*
+ * bRefClkGatingWaitTime defines the minimum
+ * time for which the reference clock is
+ * required by device during transition from
+ * HS-MODE to LS-MODE or HIBERN8 state. Give it
+ * more time to be on the safe side.
+ */
+ gating_wait += 10;
+ usleep_range(gating_wait, gating_wait + 10);
+ }
+ }
writel_relaxed(temp, host->dev_ref_clk_ctrl_mmio);
--
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