[PATCH V3 8/9] scsi: ufs: qcom : Introduce phy_power_on/off wrapper function

Nitin Rawat
2025-04-10T09:01:38Z

Introduce ufs_qcom_phy_power_on and ufs_qcom_phy_power_off wrapper
functions with mutex protection to ensure safe usage of is_phy_pwr_on
and prevent possible race conditions.

Co-developed-by: Can Guo <quic_cang@quicinc.com>
Signed-off-by: Can Guo <quic_cang@quicinc.com>
Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
---
drivers/ufs/host/ufs-qcom.c | 44 +++++++++++++++++++++++++++++++------
drivers/ufs/host/ufs-qcom.h | 4 ++++
2 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 197e84d47eec..6a7b51e0759c 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -421,6 +421,38 @@ static u32 ufs_qcom_get_hs_gear(struct ufs_hba *hba)
return UFS_HS_G3;
}

+static int ufs_qcom_phy_power_on(struct ufs_hba *hba)
+{
+ struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+ struct phy *phy = host->generic_phy;
+ int ret = 0;
+
+ guard(mutex)(&host->phy_mutex);
+ if (!host->is_phy_pwr_on) {
+ ret = phy_power_on(phy);
+ if (!ret)
+ host->is_phy_pwr_on = true;
+ }
+
+ return ret;
+}
+
+static int ufs_qcom_phy_power_off(struct ufs_hba *hba)
+{
+ struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+ struct phy *phy = host->generic_phy;
+ int ret = 0;
+
+ guard(mutex)(&host->phy_mutex);
+ if (host->is_phy_pwr_on) {
+ ret = phy_power_off(phy);
+ if (!ret)
+ host->is_phy_pwr_on = false;
+ }
+
+ return ret;
+}
+
static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
{
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
@@ -449,7 +481,7 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
return ret;

if (phy->power_count) {
- phy_power_off(phy);
+ ufs_qcom_phy_power_off(hba);
phy_exit(phy);
}

@@ -466,7 +498,7 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
goto out_disable_phy;

/* power on phy - start serdes and phy's power and clocks */
- ret = phy_power_on(phy);
+ ret = ufs_qcom_phy_power_on(hba);
if (ret) {
dev_err(hba->dev, "%s: phy power on failed, ret = %d\n",
__func__, ret);
@@ -1018,7 +1050,6 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
enum ufs_notify_change_status status)
{
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
- struct phy *phy = host->generic_phy;
int err;

/*
@@ -1038,7 +1069,7 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
/* disable device ref_clk */
ufs_qcom_dev_ref_clk_ctrl(host, false);
}
- err = phy_power_off(phy);
+ err = ufs_qcom_phy_power_off(hba);
if (err) {
dev_err(hba->dev, "%s: phy power off failed, ret=%d\n",
__func__, err);
@@ -1048,7 +1079,7 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
break;
case POST_CHANGE:
if (on) {
- err = phy_power_on(phy);
+ err = ufs_qcom_phy_power_on(hba);
if (err) {
dev_err(hba->dev, "%s: phy power on failed, ret = %d\n",
__func__, err);
@@ -1236,10 +1267,9 @@ static int ufs_qcom_init(struct ufs_hba *hba)
static void ufs_qcom_exit(struct ufs_hba *hba)
{
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
- struct phy *phy = host->generic_phy;

ufs_qcom_disable_lane_clks(host);
- phy_power_off(phy);
+ ufs_qcom_phy_power_off(hba);
phy_exit(host->generic_phy);
}

diff --git a/drivers/ufs/host/ufs-qcom.h b/drivers/ufs/host/ufs-qcom.h
index d0e6ec9128e7..3db29fbcd40b 100644
--- a/drivers/ufs/host/ufs-qcom.h
+++ b/drivers/ufs/host/ufs-qcom.h
@@ -252,6 +252,10 @@ struct ufs_qcom_host {
u32 phy_gear;

bool esi_enabled;
+ /* flag to check if phy is powered on */
+ bool is_phy_pwr_on;
+ /* Protect the usage of is_phy_pwr_on against racing */
+ struct mutex phy_mutex;
};

struct ufs_qcom_drvdata {
--
2.48.1