On 2020-02-17 17:35, Stanley Chu wrote:
In UFS version 3.0, a newly added attribute bRefClkGatingWaitTime
defines
the minimum time for which the reference clock is required by device
during
transition to LS-MODE or HIBERN8 state.
Currently this time is detected and stored in
hba->dev_info.clk_gating_wait_us but applied to vendor implementatios
only.
Make it applied to reference clock named as "ref_clk" in device tree in
common path.
Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 744b8254220c..7f60721f54d1 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -7417,8 +7417,10 @@ static int __ufshcd_setup_clocks(struct ufs_hba
*hba, bool on,
struct ufs_clk_info *clki;
struct list_head *head = &hba->clk_list_head;
unsigned long flags;
+ unsigned long wait_us;
ktime_t start = ktime_get();
bool clk_state_changed = false;
+ bool ref_clk;
if (list_empty(head))
goto out;
@@ -7436,7 +7438,8 @@ static int __ufshcd_setup_clocks(struct ufs_hba
*hba, bool on,
list_for_each_entry(clki, head, list) {
if (!IS_ERR_OR_NULL(clki->clk)) {
- if (skip_ref_clk && !strcmp(clki->name, "ref_clk"))
+ ref_clk = !strcmp(clki->name, "ref_clk") ? true : false;
+ if (skip_ref_clk && ref_clk)
continue;
clk_state_changed = on ^ clki->enabled;
@@ -7449,6 +7452,9 @@ static int __ufshcd_setup_clocks(struct ufs_hba
*hba, bool on,
}
} else if (!on && clki->enabled) {
clk_disable_unprepare(clki->clk);
+ wait_us = hba->dev_info.clk_gating_wait_us;
+ if (ref_clk && wait_us)
+ usleep_range(wait_us, wait_us + 10);
Hi Stanley,
If wait_us is 1us, it would be inappropriate to use usleep_range() here.
You have checks of the delay in patch #2, but why it is not needed here?
Thanks,
Can Guo.
}
clki->enabled = on;
dev_dbg(hba->dev, "%s: clk: %s %sabled\n", __func__,
