[PATCH 5.10 444/575] scsi: ufs: Refactor ufshcd_setup_clocks() to remove skip_ref_clk

From: Greg Kroah-Hartman
Date: Mon Nov 15 2021 - 15:34:54 EST


From: Can Guo <cang@xxxxxxxxxxxxxx>

[ Upstream commit 81309c247a4dcd597cbda5254fd0afdd61b93f14 ]

Remove the param skip_ref_clk from __ufshcd_setup_clocks(), but keep a flag
in struct ufs_clk_info to tell whether a clock can be disabled or not while
the link is active.

Link: https://lore.kernel.org/r/1606356063-38380-2-git-send-email-cang@xxxxxxxxxxxxxx
Reviewed-by: Hongwu Su <hongwus@xxxxxxxxxxxxxx>
Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
Reviewed-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd-pltfrm.c | 2 ++
drivers/scsi/ufs/ufshcd.c | 29 +++++++++--------------------
drivers/scsi/ufs/ufshcd.h | 3 +++
3 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index 24927cf485b47..68ce209577eca 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -92,6 +92,8 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
clki->min_freq = clkfreq[i];
clki->max_freq = clkfreq[i+1];
clki->name = kstrdup(name, GFP_KERNEL);
+ if (!strcmp(name, "ref_clk"))
+ clki->keep_link_active = true;
dev_dbg(dev, "%s: min %u max %u name %s\n", "freq-table-hz",
clki->min_freq, clki->max_freq, clki->name);
list_add_tail(&clki->list, &hba->clk_list_head);
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 3139d9df6f320..930f35863cbb5 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -221,8 +221,6 @@ static int ufshcd_eh_host_reset_handler(struct scsi_cmnd *cmd);
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);
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);
@@ -1714,11 +1712,7 @@ static void ufshcd_gate_work(struct work_struct *work)

ufshcd_disable_irq(hba);

- 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);
+ ufshcd_setup_clocks(hba, false);

/*
* In case you are here to cancel this work the gating state
@@ -8055,8 +8049,7 @@ static int ufshcd_init_hba_vreg(struct ufs_hba *hba)
return 0;
}

-static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
- bool skip_ref_clk)
+static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on)
{
int ret = 0;
struct ufs_clk_info *clki;
@@ -8074,7 +8067,12 @@ 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"))
+ /*
+ * Don't disable clocks which are needed
+ * to keep the link active.
+ */
+ if (ufshcd_is_link_active(hba) &&
+ clki->keep_link_active)
continue;

clk_state_changed = on ^ clki->enabled;
@@ -8119,11 +8117,6 @@ out:
return ret;
}

-static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on)
-{
- return __ufshcd_setup_clocks(hba, on, false);
-}
-
static int ufshcd_init_clocks(struct ufs_hba *hba)
{
int ret = 0;
@@ -8642,11 +8635,7 @@ disable_clks:
*/
ufshcd_disable_irq(hba);

- 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);
+ ufshcd_setup_clocks(hba, false);

if (ufshcd_is_clkgating_allowed(hba)) {
hba->clk_gating.state = CLKS_OFF;
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 812aa348751eb..1ba9c786feb6d 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -229,6 +229,8 @@ struct ufs_dev_cmd {
* @max_freq: maximum frequency supported by the clock
* @min_freq: min frequency that can be used for clock scaling
* @curr_freq: indicates the current frequency that it is set to
+ * @keep_link_active: indicates that the clk should not be disabled if
+ link is active
* @enabled: variable to check against multiple enable/disable
*/
struct ufs_clk_info {
@@ -238,6 +240,7 @@ struct ufs_clk_info {
u32 max_freq;
u32 min_freq;
u32 curr_freq;
+ bool keep_link_active;
bool enabled;
};

--
2.33.0