[PATCH] scsi: ufs: Don't disable core_clk_unipro if the link is active

From: Can Guo
Date: Tue Nov 24 2020 - 00:05:17 EST


If we want to disable clocks but still keep the link active, both ref_clk
and core_clk_unipro should be skipped.

Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a7857f6..69c2e91 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -222,7 +222,7 @@ static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag);
static void ufshcd_hba_exit(struct ufs_hba *hba);
static int ufshcd_probe_hba(struct ufs_hba *hba, bool async);
static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
- bool skip_ref_clk);
+ bool keep_link_active);
static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on);
static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba);
@@ -1710,7 +1710,6 @@ static void ufshcd_gate_work(struct work_struct *work)
if (!ufshcd_is_link_active(hba))
ufshcd_setup_clocks(hba, false);
else
- /* If link is active, device ref_clk can't be switched off */
__ufshcd_setup_clocks(hba, false, true);

/*
@@ -7991,7 +7990,7 @@ static int ufshcd_init_hba_vreg(struct ufs_hba *hba)
}

static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
- bool skip_ref_clk)
+ bool keep_link_active)
{
int ret = 0;
struct ufs_clk_info *clki;
@@ -8009,7 +8008,13 @@ 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"))
+ /*
+ * To keep link active, ref_clk and core_clk_unipro
+ * should be kept ON.
+ */
+ if (keep_link_active &&
+ (!strcmp(clki->name, "ref_clk") ||
+ !strcmp(clki->name, "core_clk_unipro")))
continue;

clk_state_changed = on ^ clki->enabled;
@@ -8580,7 +8585,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
if (!ufshcd_is_link_active(hba))
ufshcd_setup_clocks(hba, false);
else
- /* If link is active, device ref_clk can't be switched off */
__ufshcd_setup_clocks(hba, false, true);

if (ufshcd_is_clkgating_allowed(hba)) {
--
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