[PATCH V2 0/6] Refactor phy powerup sequence

[PATCH V2 0/6] Refactor phy powerup sequence

[Nitin Rawat]

Refactor phy_power_on and phy_calibrate callbacks.

In Current code regulators enable, clks enable, calibrating UFS PHY,
start_serdes and polling PCS_ready_status are part of phy_power_on.

UFS PHY registers are retained after power collapse, meaning calibrating
UFS PHY, start_serdes and polling PCS_ready_status can be done only when
hba is powered_on, and not needed every time when phy_power_on is called
during resume. Hence keep the code which enables PHY's regulators & clks
in phy_power_on and move the rest steps into phy_calibrate function.

Since phy_power_on is separated out from phy calibrate, make separate calls
to phy_power_on and phy_calibrate calls from ufs qcom driver.

Also for better power saving, remove the phy_power_on/off calls from
resume/suspend path and put them to ufs_qcom_setup_clocks, so that
PHY's regulators & clks can be turned on/off along with UFS's clocks.

This patch series is tested on SM8550 QRD, SM8650 MTP , SM8750 MTP.

There is functional dependency between ufs-qcom and phy-qcom-qmp-ufs
and hence both the patches should be part of same merge window.

Changes in v2:
1. Addressed vinod koul and manivannan comment to split the phy patch
   into multiple patches.
2. Addressed vinod's comment to reuse SW_PWRDN instead of creating
   new macros SW_PWRUP in phy-qcom-qmp-ufs.c.
3. Addressed Konrad's comment to optimize mutex lock in ufs-qcom.c
4. Addressed konrad and Manivannan comment to clean debug print in
   ufs-qcom.c

Link to V1: https://lore.kernel.org/linux-kernel/20240112153348.2778-1-quic_nitirawa@quicinc.com/
---
Nitin Rawat (6):
  phy: qcom-qmp-ufs: Rename qmp_ufs_enable and qmp_ufs_power_on
  phy: qcom-qmp-ufs: Refactor phy_power_on and phy_calibrate callbacks
  phy: qcom-qmp-ufs: Refactor UFS PHY reset
  phy: qcom-qmp-ufs: Refactor qmp_ufs_exit callback.
  scsi: ufs: qcom : Refactor phy_power_on/off calls
  scsi: ufs: host : Introduce phy_power_on/off wrapper function

 drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 141 ++++++++----------------
 drivers/ufs/host/ufs-qcom.c             |  92 ++++++++++------
 drivers/ufs/host/ufs-qcom.h             |   4 +
 3 files changed, 106 insertions(+), 131 deletions(-)

--
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[PATCH V2 1/6] phy: qcom-qmp-ufs: Rename qmp_ufs_enable and qmp_ufs_power_on

[Nitin Rawat]

Rename qmp_ufs_enable to qmp_ufs_power_on and qmp_ufs_power_on to
qmp_ufs_phy_calibrate to better reflect functionality. Also
update function calls and structure assignments accordingly.

Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
index 45b3b792696e..bb836bc0f736 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
@@ -1837,7 +1837,7 @@ static int qmp_ufs_init(struct phy *phy)
 	return 0;
 }

-static int qmp_ufs_power_on(struct phy *phy)
+static int qmp_ufs_phy_calibrate(struct phy *phy)
 {
 	struct qmp_ufs *qmp = phy_get_drvdata(phy);
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
@@ -1898,7 +1898,7 @@ static int qmp_ufs_exit(struct phy *phy)
 	return 0;
 }

-static int qmp_ufs_enable(struct phy *phy)
+static int qmp_ufs_power_on(struct phy *phy)
 {
 	int ret;

@@ -1906,7 +1906,7 @@ static int qmp_ufs_enable(struct phy *phy)
 	if (ret)
 		return ret;

-	ret = qmp_ufs_power_on(phy);
+	ret = qmp_ufs_phy_calibrate(phy);
 	if (ret)
 		qmp_ufs_exit(phy);

@@ -1940,7 +1940,7 @@ static int qmp_ufs_set_mode(struct phy *phy, enum phy_mode mode, int submode)
 }

 static const struct phy_ops qcom_qmp_ufs_phy_ops = {
-	.power_on	= qmp_ufs_enable,
+	.power_on	= qmp_ufs_power_on,
 	.power_off	= qmp_ufs_disable,
 	.set_mode	= qmp_ufs_set_mode,
 	.owner		= THIS_MODULE,
--
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[PATCH V2 2/6] phy: qcom-qmp-ufs: Refactor phy_power_on and phy_calibrate callbacks

[Nitin Rawat]

Commit 052553af6a31 ("ufs/phy: qcom: Refactor to use phy_init call")
puts enabling regulators & clks, calibrating UFS PHY, starting serdes
and polling PCS ready status into phy_power_on.

In Current code regulators enable, clks enable, calibrating UFS PHY,
start_serdes and polling PCS_ready_status are part of phy_power_on.

UFS PHY registers are retained after power collapse, meaning calibrating
UFS PHY, start_serdes and polling PCS_ready_status can be done only when
hba is powered_on, and not needed every time when phy_power_on is called
during resume. Hence keep the code which enables PHY's regulators & clks
in phy_power_on and move the rest steps into phy_calibrate function.

Refactor the code to retain PHY regulators & clks in phy_power_on and
move out rest of the code to new phy_calibrate function.

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/phy/qualcomm/phy-qcom-qmp-ufs.c | 18 ++----------------
 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
index bb836bc0f736..0089ee80f852 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
@@ -1796,7 +1796,7 @@ static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
 	return 0;
 }

-static int qmp_ufs_init(struct phy *phy)
+static int qmp_ufs_power_on(struct phy *phy)
 {
 	struct qmp_ufs *qmp = phy_get_drvdata(phy);
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
@@ -1898,21 +1898,6 @@ static int qmp_ufs_exit(struct phy *phy)
 	return 0;
 }

-static int qmp_ufs_power_on(struct phy *phy)
-{
-	int ret;
-
-	ret = qmp_ufs_init(phy);
-	if (ret)
-		return ret;
-
-	ret = qmp_ufs_phy_calibrate(phy);
-	if (ret)
-		qmp_ufs_exit(phy);
-
-	return ret;
-}
-
 static int qmp_ufs_disable(struct phy *phy)
 {
 	int ret;
@@ -1942,6 +1927,7 @@ static int qmp_ufs_set_mode(struct phy *phy, enum phy_mode mode, int submode)
 static const struct phy_ops qcom_qmp_ufs_phy_ops = {
 	.power_on	= qmp_ufs_power_on,
 	.power_off	= qmp_ufs_disable,
+	.calibrate	= qmp_ufs_phy_calibrate,
 	.set_mode	= qmp_ufs_set_mode,
 	.owner		= THIS_MODULE,
 };
--
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[PATCH V2 3/6] phy: qcom-qmp-ufs: Refactor UFS PHY reset

[Nitin Rawat]

Refactor the UFS PHY reset handling to parse the reset logic only once
during probe, instead of every resume.

Move the UFS PHY reset parsing logic from qmp_phy_power_on to
qmp_ufs_probe to avoid unnecessary parsing during resume.

Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 104 ++++++++++++------------
 1 file changed, 50 insertions(+), 54 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
index 0089ee80f852..3a80c2c110d2 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
@@ -1757,32 +1757,6 @@ static void qmp_ufs_init_registers(struct qmp_ufs *qmp, const struct qmp_phy_cfg
 	qmp_ufs_init_all(qmp, &cfg->tbls_hs_b);
 }

-static int qmp_ufs_com_init(struct qmp_ufs *qmp)
-{
-	const struct qmp_phy_cfg *cfg = qmp->cfg;
-	void __iomem *pcs = qmp->pcs;
-	int ret;
-
-	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
-	if (ret) {
-		dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
-		return ret;
-	}
-
-	ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
-	if (ret)
-		goto err_disable_regulators;
-
-	qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
-
-	return 0;
-
-err_disable_regulators:
-	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
-
-	return ret;
-}
-
 static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
 {
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
@@ -1800,41 +1774,27 @@ static int qmp_ufs_power_on(struct phy *phy)
 {
 	struct qmp_ufs *qmp = phy_get_drvdata(phy);
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
+	void __iomem *pcs = qmp->pcs;
 	int ret;
-	dev_vdbg(qmp->dev, "Initializing QMP phy\n");
-
-	if (cfg->no_pcs_sw_reset) {
-		/*
-		 * Get UFS reset, which is delayed until now to avoid a
-		 * circular dependency where UFS needs its PHY, but the PHY
-		 * needs this UFS reset.
-		 */
-		if (!qmp->ufs_reset) {
-			qmp->ufs_reset =
-				devm_reset_control_get_exclusive(qmp->dev,
-								 "ufsphy");
-
-			if (IS_ERR(qmp->ufs_reset)) {
-				ret = PTR_ERR(qmp->ufs_reset);
-				dev_err(qmp->dev,
-					"failed to get UFS reset: %d\n",
-					ret);
-
-				qmp->ufs_reset = NULL;
-				return ret;
-			}
-		}

-		ret = reset_control_assert(qmp->ufs_reset);
-		if (ret)
-			return ret;
+	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
+	if (ret) {
+		dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
+		return ret;
 	}

-	ret = qmp_ufs_com_init(qmp);
+	ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
 	if (ret)
-		return ret;
+		goto err_disable_regulators;
+
+	qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);

 	return 0;
+
+err_disable_regulators:
+	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
+
+	return ret;
 }

 static int qmp_ufs_phy_calibrate(struct phy *phy)
@@ -1846,6 +1806,10 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
 	unsigned int val;
 	int ret;

+	ret = reset_control_assert(qmp->ufs_reset);
+	if (ret)
+		return ret;
+
 	qmp_ufs_init_registers(qmp, cfg);

 	ret = reset_control_deassert(qmp->ufs_reset);
@@ -2088,6 +2052,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
 	return 0;
 }

+static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
+{
+	const struct qmp_phy_cfg *cfg = qmp->cfg;
+	int ret;
+
+	if (!cfg->no_pcs_sw_reset)
+		return 0;
+
+	/*
+	 * Get UFS reset, which is delayed until now to avoid a
+	 * circular dependency where UFS needs its PHY, but the PHY
+	 * needs this UFS reset.
+	 */
+	if (!qmp->ufs_reset) {
+		qmp->ufs_reset =
+		devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
+
+		if (IS_ERR(qmp->ufs_reset)) {
+			ret = PTR_ERR(qmp->ufs_reset);
+			dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
+			qmp->ufs_reset = NULL;
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 static int qmp_ufs_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -2114,6 +2106,10 @@ static int qmp_ufs_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;

+	ret = qmp_ufs_get_phy_reset(qmp);
+	if (ret)
+		return ret;
+
 	/* Check for legacy binding with child node. */
 	np = of_get_next_available_child(dev->of_node, NULL);
 	if (np) {
--
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[PATCH V2 4/6] phy: qcom-qmp-ufs: Refactor qmp_ufs_exit callback.

[Nitin Rawat]

Rename qmp_ufs_disable to qmp_ufs_power_off and refactor
the code to move all the power off sequence to qmp_ufs_power_off.

Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 41 ++-----------------------
 1 file changed, 3 insertions(+), 38 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
index 3a80c2c110d2..675fef106d3b 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
@@ -1757,19 +1757,6 @@ static void qmp_ufs_init_registers(struct qmp_ufs *qmp, const struct qmp_phy_cfg
 	qmp_ufs_init_all(qmp, &cfg->tbls_hs_b);
 }

-static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
-{
-	const struct qmp_phy_cfg *cfg = qmp->cfg;
-
-	reset_control_assert(qmp->ufs_reset);
-
-	clk_bulk_disable_unprepare(qmp->num_clks, qmp->clks);
-
-	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
-
-	return 0;
-}
-
 static int qmp_ufs_power_on(struct phy *phy)
 {
 	struct qmp_ufs *qmp = phy_get_drvdata(phy);
@@ -1839,39 +1826,17 @@ static int qmp_ufs_power_off(struct phy *phy)
 	struct qmp_ufs *qmp = phy_get_drvdata(phy);
 	const struct qmp_phy_cfg *cfg = qmp->cfg;

-	/* PHY reset */
-	if (!cfg->no_pcs_sw_reset)
-		qphy_setbits(qmp->pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);
-
-	/* stop SerDes */
-	qphy_clrbits(qmp->pcs, cfg->regs[QPHY_START_CTRL], SERDES_START);
-
 	/* Put PHY into POWER DOWN state: active low */
 	qphy_clrbits(qmp->pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL],
 			SW_PWRDN);

-	return 0;
-}
-
-static int qmp_ufs_exit(struct phy *phy)
-{
-	struct qmp_ufs *qmp = phy_get_drvdata(phy);
+	clk_bulk_disable_unprepare(qmp->num_clks, qmp->clks);

-	qmp_ufs_com_exit(qmp);
+	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);

 	return 0;
 }

-static int qmp_ufs_disable(struct phy *phy)
-{
-	int ret;
-
-	ret = qmp_ufs_power_off(phy);
-	if (ret)
-		return ret;
-	return qmp_ufs_exit(phy);
-}
-
 static int qmp_ufs_set_mode(struct phy *phy, enum phy_mode mode, int submode)
 {
 	struct qmp_ufs *qmp = phy_get_drvdata(phy);
@@ -1890,7 +1855,7 @@ static int qmp_ufs_set_mode(struct phy *phy, enum phy_mode mode, int submode)

 static const struct phy_ops qcom_qmp_ufs_phy_ops = {
 	.power_on	= qmp_ufs_power_on,
-	.power_off	= qmp_ufs_disable,
+	.power_off	= qmp_ufs_power_off,
 	.calibrate	= qmp_ufs_phy_calibrate,
 	.set_mode	= qmp_ufs_set_mode,
 	.owner		= THIS_MODULE,
--
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[PATCH V2 5/6] scsi: ufs: qcom : Refactor phy_power_on/off calls

[Nitin Rawat]

Commit 3f6d1767b1a0 ("phy: ufs-qcom: Refactor all init steps into
phy_poweron") removes the phy_power_on/off from ufs_qcom_setup_clocks
to suspend/resume func.

To have a better power saving, remove the phy_power_on/off calls from
resume/suspend path and put them back to ufs_qcom_setup_clocks, so that
PHY regulators & clks can be turned on/off along with UFS's clocks.

Since phy phy_power_on is separated out from phy calibrate, make
separate calls to phy_power_on and phy_calibrate calls from ufs qcom
driver.

Co-developed-by: Can Guo <quic_cang@quicinc.com>
Signed-off-by: Can Guo <quic_cang@quicinc.com>
Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
---
 drivers/ufs/host/ufs-qcom.c | 58 +++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 32 deletions(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 1b37449fbffc..5c7b6c75d669 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -473,6 +473,11 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
 		goto out_disable_phy;
 	}

+	ret = phy_calibrate(phy);
+	if (ret) {
+		dev_err(hba->dev, "Failed to calibrate PHY %d\n", ret);
+		goto out_disable_phy;
+	}
 	ufs_qcom_select_unipro_mode(host);

 	return 0;
@@ -633,26 +638,17 @@ static int ufs_qcom_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op,
 	enum ufs_notify_change_status status)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
-	struct phy *phy = host->generic_phy;

 	if (status == PRE_CHANGE)
 		return 0;

-	if (ufs_qcom_is_link_off(hba)) {
-		/*
-		 * Disable the tx/rx lane symbol clocks before PHY is
-		 * powered down as the PLL source should be disabled
-		 * after downstream clocks are disabled.
-		 */
+	if (!ufs_qcom_is_link_active(hba))
 		ufs_qcom_disable_lane_clks(host);
-		phy_power_off(phy);

-		/* reset the connected UFS device during power down */
-		ufs_qcom_device_reset_ctrl(hba, true);

-	} else if (!ufs_qcom_is_link_active(hba)) {
-		ufs_qcom_disable_lane_clks(host);
-	}
+	/* reset the connected UFS device during power down */
+	if (ufs_qcom_is_link_off(hba) && host->device_reset)
+		ufs_qcom_device_reset_ctrl(hba, true);

 	return ufs_qcom_ice_suspend(host);
 }
@@ -660,26 +656,11 @@ static int ufs_qcom_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op,
 static int ufs_qcom_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
-	struct phy *phy = host->generic_phy;
 	int err;

-	if (ufs_qcom_is_link_off(hba)) {
-		err = phy_power_on(phy);
-		if (err) {
-			dev_err(hba->dev, "%s: failed PHY power on: %d\n",
-				__func__, err);
-			return err;
-		}
-
-		err = ufs_qcom_enable_lane_clks(host);
-		if (err)
-			return err;
-
-	} else if (!ufs_qcom_is_link_active(hba)) {
-		err = ufs_qcom_enable_lane_clks(host);
-		if (err)
-			return err;
-	}
+	err = ufs_qcom_enable_lane_clks(host);
+	if (err)
+		return err;

 	return ufs_qcom_ice_resume(host);
 }
@@ -1036,6 +1017,8 @@ 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;

 	/*
 	 * In case ufs_qcom_init() is not yet done, simply ignore.
@@ -1054,10 +1037,20 @@ 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);
+			if (err) {
+				dev_err(hba->dev, "phy power off failed, ret=%d\n", err);
+					return err;
+			}
 		}
 		break;
 	case POST_CHANGE:
 		if (on) {
+			err = phy_power_on(phy);
+			if (err) {
+				dev_err(hba->dev, "phy power on failed, ret = %d\n", err);
+				return err;
+			}
 			/* enable the device ref clock for HS mode*/
 			if (ufshcd_is_hs_mode(&hba->pwr_info))
 				ufs_qcom_dev_ref_clk_ctrl(host, true);
@@ -1240,9 +1233,10 @@ 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(host->generic_phy);
+	phy_power_off(phy);
 	phy_exit(host->generic_phy);
 }

--
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[PATCH V2 6/6] scsi: ufs: host : Introduce phy_power_on/off wrapper function

[Nitin Rawat]

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 5c7b6c75d669..8f80724e64b9 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);
@@ -1017,7 +1049,6 @@ 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;

 	/*
@@ -1037,7 +1068,7 @@ 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, "phy power off failed, ret=%d\n", err);
 					return err;
@@ -1046,7 +1077,7 @@ 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, "phy power on failed, ret = %d\n", err);
 				return err;
@@ -1233,10 +1264,9 @@ 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 {
--
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Re: [PATCH V2 1/6] phy: qcom-qmp-ufs: Rename qmp_ufs_enable and qmp_ufs_power_on

[neil.armstrong]

On 18/03/2025 15:49, Nitin Rawat wrote:
> Rename qmp_ufs_enable to qmp_ufs_power_on and qmp_ufs_power_on to
> qmp_ufs_phy_calibrate to better reflect functionality. Also
> update function calls and structure assignments accordingly.
> 
> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
> ---
>   drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> index 45b3b792696e..bb836bc0f736 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> @@ -1837,7 +1837,7 @@ static int qmp_ufs_init(struct phy *phy)
>   	return 0;
>   }
> 
> -static int qmp_ufs_power_on(struct phy *phy)
> +static int qmp_ufs_phy_calibrate(struct phy *phy)
>   {
>   	struct qmp_ufs *qmp = phy_get_drvdata(phy);
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
> @@ -1898,7 +1898,7 @@ static int qmp_ufs_exit(struct phy *phy)
>   	return 0;
>   }
> 
> -static int qmp_ufs_enable(struct phy *phy)
> +static int qmp_ufs_power_on(struct phy *phy)
>   {
>   	int ret;
> 
> @@ -1906,7 +1906,7 @@ static int qmp_ufs_enable(struct phy *phy)
>   	if (ret)
>   		return ret;
> 
> -	ret = qmp_ufs_power_on(phy);
> +	ret = qmp_ufs_phy_calibrate(phy);
>   	if (ret)
>   		qmp_ufs_exit(phy);
> 
> @@ -1940,7 +1940,7 @@ static int qmp_ufs_set_mode(struct phy *phy, enum phy_mode mode, int submode)
>   }
> 
>   static const struct phy_ops qcom_qmp_ufs_phy_ops = {
> -	.power_on	= qmp_ufs_enable,
> +	.power_on	= qmp_ufs_power_on,
>   	.power_off	= qmp_ufs_disable,
>   	.set_mode	= qmp_ufs_set_mode,
>   	.owner		= THIS_MODULE,
> --
> 2.48.1
> 
> 

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

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Re: [PATCH V2 2/6] phy: qcom-qmp-ufs: Refactor phy_power_on and phy_calibrate callbacks

[neil.armstrong]

On 18/03/2025 15:49, Nitin Rawat wrote:
> Commit 052553af6a31 ("ufs/phy: qcom: Refactor to use phy_init call")
> puts enabling regulators & clks, calibrating UFS PHY, starting serdes
> and polling PCS ready status into phy_power_on.
> 
> In Current code regulators enable, clks enable, calibrating UFS PHY,
> start_serdes and polling PCS_ready_status are part of phy_power_on.
> 
> UFS PHY registers are retained after power collapse, meaning calibrating
> UFS PHY, start_serdes and polling PCS_ready_status can be done only when
> hba is powered_on, and not needed every time when phy_power_on is called
> during resume. Hence keep the code which enables PHY's regulators & clks
> in phy_power_on and move the rest steps into phy_calibrate function.
> 
> Refactor the code to retain PHY regulators & clks in phy_power_on and
> move out rest of the code to new phy_calibrate function.
> 
> 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/phy/qualcomm/phy-qcom-qmp-ufs.c | 18 ++----------------
>   1 file changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> index bb836bc0f736..0089ee80f852 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> @@ -1796,7 +1796,7 @@ static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
>   	return 0;
>   }
> 
> -static int qmp_ufs_init(struct phy *phy)
> +static int qmp_ufs_power_on(struct phy *phy)
>   {
>   	struct qmp_ufs *qmp = phy_get_drvdata(phy);
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
> @@ -1898,21 +1898,6 @@ static int qmp_ufs_exit(struct phy *phy)
>   	return 0;
>   }
> 
> -static int qmp_ufs_power_on(struct phy *phy)
> -{
> -	int ret;
> -
> -	ret = qmp_ufs_init(phy);
> -	if (ret)
> -		return ret;
> -
> -	ret = qmp_ufs_phy_calibrate(phy);
> -	if (ret)
> -		qmp_ufs_exit(phy);
> -
> -	return ret;
> -}
> -
>   static int qmp_ufs_disable(struct phy *phy)
>   {
>   	int ret;
> @@ -1942,6 +1927,7 @@ static int qmp_ufs_set_mode(struct phy *phy, enum phy_mode mode, int submode)
>   static const struct phy_ops qcom_qmp_ufs_phy_ops = {
>   	.power_on	= qmp_ufs_power_on,
>   	.power_off	= qmp_ufs_disable,
> +	.calibrate	= qmp_ufs_phy_calibrate,

Ok so this will break the UFS until patch 5 is applied,
breaking bisectability.

Make sure UFS host driver calls calibrate first, and then
do the refactor in the PHY driver.

And either all would go in a single tree or either PHY
or SCSI maintainer would need to provide an immutable
branch for the final merge.

>   	.set_mode	= qmp_ufs_set_mode,
>   	.owner		= THIS_MODULE,
>   };
> --
> 2.48.1
> 
> 


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Re: [PATCH V2 3/6] phy: qcom-qmp-ufs: Refactor UFS PHY reset

[neil.armstrong]

On 18/03/2025 15:49, Nitin Rawat wrote:
> Refactor the UFS PHY reset handling to parse the reset logic only once
> during probe, instead of every resume.
> 
> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
> qmp_ufs_probe to avoid unnecessary parsing during resume.
> 
> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
> ---
>   drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 104 ++++++++++++------------
>   1 file changed, 50 insertions(+), 54 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> index 0089ee80f852..3a80c2c110d2 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> @@ -1757,32 +1757,6 @@ static void qmp_ufs_init_registers(struct qmp_ufs *qmp, const struct qmp_phy_cfg
>   	qmp_ufs_init_all(qmp, &cfg->tbls_hs_b);
>   }
> 
> -static int qmp_ufs_com_init(struct qmp_ufs *qmp)
> -{
> -	const struct qmp_phy_cfg *cfg = qmp->cfg;
> -	void __iomem *pcs = qmp->pcs;
> -	int ret;
> -
> -	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
> -	if (ret) {
> -		dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
> -		return ret;
> -	}
> -
> -	ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
> -	if (ret)
> -		goto err_disable_regulators;
> -
> -	qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
> -
> -	return 0;
> -
> -err_disable_regulators:
> -	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> -
> -	return ret;
> -}
> -
>   static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
>   {
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
> @@ -1800,41 +1774,27 @@ static int qmp_ufs_power_on(struct phy *phy)
>   {
>   	struct qmp_ufs *qmp = phy_get_drvdata(phy);
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
> +	void __iomem *pcs = qmp->pcs;
>   	int ret;
> -	dev_vdbg(qmp->dev, "Initializing QMP phy\n");
> -
> -	if (cfg->no_pcs_sw_reset) {
> -		/*
> -		 * Get UFS reset, which is delayed until now to avoid a
> -		 * circular dependency where UFS needs its PHY, but the PHY
> -		 * needs this UFS reset.
> -		 */
> -		if (!qmp->ufs_reset) {
> -			qmp->ufs_reset =
> -				devm_reset_control_get_exclusive(qmp->dev,
> -								 "ufsphy");
> -
> -			if (IS_ERR(qmp->ufs_reset)) {
> -				ret = PTR_ERR(qmp->ufs_reset);
> -				dev_err(qmp->dev,
> -					"failed to get UFS reset: %d\n",
> -					ret);
> -
> -				qmp->ufs_reset = NULL;
> -				return ret;
> -			}
> -		}
> 
> -		ret = reset_control_assert(qmp->ufs_reset);
> -		if (ret)
> -			return ret;
> +	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
> +	if (ret) {
> +		dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
> +		return ret;
>   	}
> 
> -	ret = qmp_ufs_com_init(qmp);
> +	ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
>   	if (ret)
> -		return ret;
> +		goto err_disable_regulators;
> +
> +	qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
> 
>   	return 0;
> +
> +err_disable_regulators:
> +	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> +
> +	return ret;
>   }

This change is too fuzzy, please introduce qmp_ufs_get_phy_reset()
in a patch, move qmp_ufs_com_init() inline in qmp_ufs_power_on()
in a second time, and finally move reset_control_assert() to
calibrate in a third patch (and explain why).

Thanks,
Neil

> 
>   static int qmp_ufs_phy_calibrate(struct phy *phy)
> @@ -1846,6 +1806,10 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
>   	unsigned int val;
>   	int ret;
> 
> +	ret = reset_control_assert(qmp->ufs_reset);
> +	if (ret)
> +		return ret;
> +
>   	qmp_ufs_init_registers(qmp, cfg);
> 
>   	ret = reset_control_deassert(qmp->ufs_reset);
> @@ -2088,6 +2052,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
>   	return 0;
>   }
> 
> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
> +{
> +	const struct qmp_phy_cfg *cfg = qmp->cfg;
> +	int ret;
> +
> +	if (!cfg->no_pcs_sw_reset)
> +		return 0;
> +
> +	/*
> +	 * Get UFS reset, which is delayed until now to avoid a
> +	 * circular dependency where UFS needs its PHY, but the PHY
> +	 * needs this UFS reset.
> +	 */
> +	if (!qmp->ufs_reset) {
> +		qmp->ufs_reset =
> +		devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
> +
> +		if (IS_ERR(qmp->ufs_reset)) {
> +			ret = PTR_ERR(qmp->ufs_reset);
> +			dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
> +			qmp->ufs_reset = NULL;
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>   static int qmp_ufs_probe(struct platform_device *pdev)
>   {
>   	struct device *dev = &pdev->dev;
> @@ -2114,6 +2106,10 @@ static int qmp_ufs_probe(struct platform_device *pdev)
>   	if (ret)
>   		return ret;
> 
> +	ret = qmp_ufs_get_phy_reset(qmp);
> +	if (ret)
> +		return ret;
> +
>   	/* Check for legacy binding with child node. */
>   	np = of_get_next_available_child(dev->of_node, NULL);
>   	if (np) {
> --
> 2.48.1
> 
> 


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Re: [PATCH V2 4/6] phy: qcom-qmp-ufs: Refactor qmp_ufs_exit callback.

[neil.armstrong]

On 18/03/2025 15:49, Nitin Rawat wrote:
> Rename qmp_ufs_disable to qmp_ufs_power_off and refactor
> the code to move all the power off sequence to qmp_ufs_power_off.
> 
> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
> ---
>   drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 41 ++-----------------------
>   1 file changed, 3 insertions(+), 38 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> index 3a80c2c110d2..675fef106d3b 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> @@ -1757,19 +1757,6 @@ static void qmp_ufs_init_registers(struct qmp_ufs *qmp, const struct qmp_phy_cfg
>   	qmp_ufs_init_all(qmp, &cfg->tbls_hs_b);
>   }
> 
> -static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
> -{
> -	const struct qmp_phy_cfg *cfg = qmp->cfg;
> -
> -	reset_control_assert(qmp->ufs_reset);
> -
> -	clk_bulk_disable_unprepare(qmp->num_clks, qmp->clks);
> -
> -	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> -
> -	return 0;
> -}
> -
>   static int qmp_ufs_power_on(struct phy *phy)
>   {
>   	struct qmp_ufs *qmp = phy_get_drvdata(phy);
> @@ -1839,39 +1826,17 @@ static int qmp_ufs_power_off(struct phy *phy)
>   	struct qmp_ufs *qmp = phy_get_drvdata(phy);
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
> 
> -	/* PHY reset */
> -	if (!cfg->no_pcs_sw_reset)
> -		qphy_setbits(qmp->pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);
> -
> -	/* stop SerDes */
> -	qphy_clrbits(qmp->pcs, cfg->regs[QPHY_START_CTRL], SERDES_START);
> -
>   	/* Put PHY into POWER DOWN state: active low */
>   	qphy_clrbits(qmp->pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL],
>   			SW_PWRDN);

So where goes this code ? I think it should go in a new exit PHY op.

> 
> -	return 0;
> -}
> -
> -static int qmp_ufs_exit(struct phy *phy)
> -{
> -	struct qmp_ufs *qmp = phy_get_drvdata(phy);
> +	clk_bulk_disable_unprepare(qmp->num_clks, qmp->clks);
> 
> -	qmp_ufs_com_exit(qmp);
> +	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> 
>   	return 0;
>   }
> 
> -static int qmp_ufs_disable(struct phy *phy)
> -{
> -	int ret;
> -
> -	ret = qmp_ufs_power_off(phy);
> -	if (ret)
> -		return ret;
> -	return qmp_ufs_exit(phy);
> -}
> -
>   static int qmp_ufs_set_mode(struct phy *phy, enum phy_mode mode, int submode)
>   {
>   	struct qmp_ufs *qmp = phy_get_drvdata(phy);
> @@ -1890,7 +1855,7 @@ static int qmp_ufs_set_mode(struct phy *phy, enum phy_mode mode, int submode)
> 
>   static const struct phy_ops qcom_qmp_ufs_phy_ops = {
>   	.power_on	= qmp_ufs_power_on,
> -	.power_off	= qmp_ufs_disable,
> +	.power_off	= qmp_ufs_power_off,
>   	.calibrate	= qmp_ufs_phy_calibrate,
>   	.set_mode	= qmp_ufs_set_mode,
>   	.owner		= THIS_MODULE,
> --
> 2.48.1
> 
> 


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Re: [PATCH V2 6/6] scsi: ufs: host : Introduce phy_power_on/off wrapper function

[Bart Van Assche]

On 3/18/25 7:49 AM, Nitin Rawat wrote:

Just like the other patches in this series, the subject of this patch
should have the prefix "scsi: ufs: qcom:" instead of "scsi: ufs: host:"

> 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;
>   };

Please reorder the above two structure members. Synchronization objects
should occur before the data members protected by these synchronization
objects in structure definitions.

It seems to me that phy_mutex not only serializes is_phy_pwr_on accesses
but that it also serializes phy_power_on() / phy_power_off() calls. If
this is the case, please mention this.

Thanks,

Bart.

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Re: [PATCH V2 3/6] phy: qcom-qmp-ufs: Refactor UFS PHY reset

[Bjorn Andersson]

On Tue, Mar 18, 2025 at 08:19:41PM +0530, Nitin Rawat wrote:
> Refactor the UFS PHY reset handling to parse the reset logic only once
> during probe, instead of every resume.
> 

This looks very reasonable! But it would be preferred to see the commit
messages following the what format outlines in
https://docs.kernel.org/process/submitting-patches.html#describe-your-changes
with a clear problem description followed by a description of the
technical solution.

> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
> qmp_ufs_probe to avoid unnecessary parsing during resume.

Please add ()-suffix to function names in your commit messages.

Also, this series moves things around a lot, can you confirm that UFS is
working inbetween each one of this patches, so that the branch is
bisectable when this is being picked up?

> 
> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 104 ++++++++++++------------
>  1 file changed, 50 insertions(+), 54 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> index 0089ee80f852..3a80c2c110d2 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> @@ -1757,32 +1757,6 @@ static void qmp_ufs_init_registers(struct qmp_ufs *qmp, const struct qmp_phy_cfg
>  	qmp_ufs_init_all(qmp, &cfg->tbls_hs_b);
>  }
> 
> -static int qmp_ufs_com_init(struct qmp_ufs *qmp)
> -{
> -	const struct qmp_phy_cfg *cfg = qmp->cfg;
> -	void __iomem *pcs = qmp->pcs;
> -	int ret;
> -
> -	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
> -	if (ret) {
> -		dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
> -		return ret;
> -	}
> -
> -	ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
> -	if (ret)
> -		goto err_disable_regulators;
> -
> -	qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
> -
> -	return 0;
> -
> -err_disable_regulators:
> -	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> -
> -	return ret;
> -}
> -
>  static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
>  {
>  	const struct qmp_phy_cfg *cfg = qmp->cfg;
> @@ -1800,41 +1774,27 @@ static int qmp_ufs_power_on(struct phy *phy)
>  {
>  	struct qmp_ufs *qmp = phy_get_drvdata(phy);
>  	const struct qmp_phy_cfg *cfg = qmp->cfg;
> +	void __iomem *pcs = qmp->pcs;

This is only used once, perhaps not worth a local variable to save 5
characters on that line?

>  	int ret;
> -	dev_vdbg(qmp->dev, "Initializing QMP phy\n");
> -
> -	if (cfg->no_pcs_sw_reset) {
> -		/*
> -		 * Get UFS reset, which is delayed until now to avoid a
> -		 * circular dependency where UFS needs its PHY, but the PHY
> -		 * needs this UFS reset.
> -		 */
> -		if (!qmp->ufs_reset) {
> -			qmp->ufs_reset =
> -				devm_reset_control_get_exclusive(qmp->dev,
> -								 "ufsphy");
> -
> -			if (IS_ERR(qmp->ufs_reset)) {
> -				ret = PTR_ERR(qmp->ufs_reset);
> -				dev_err(qmp->dev,
> -					"failed to get UFS reset: %d\n",
> -					ret);
> -
> -				qmp->ufs_reset = NULL;
> -				return ret;
> -			}
> -		}
> 
> -		ret = reset_control_assert(qmp->ufs_reset);
> -		if (ret)
> -			return ret;
> +	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
> +	if (ret) {
> +		dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);

regulator_bulk_enable() will already have printed a more useful error
message, letting you know which of the vregs[] it was that failed to
enable.

> +		return ret;
>  	}
> 
> -	ret = qmp_ufs_com_init(qmp);
> +	ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
>  	if (ret)
> -		return ret;
> +		goto err_disable_regulators;
> +
> +	qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
> 
>  	return 0;
> +
> +err_disable_regulators:
> +	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> +
> +	return ret;
>  }
> 
>  static int qmp_ufs_phy_calibrate(struct phy *phy)
> @@ -1846,6 +1806,10 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
>  	unsigned int val;
>  	int ret;
> 
> +	ret = reset_control_assert(qmp->ufs_reset);
> +	if (ret)
> +		return ret;
> +
>  	qmp_ufs_init_registers(qmp, cfg);
> 
>  	ret = reset_control_deassert(qmp->ufs_reset);
> @@ -2088,6 +2052,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
>  	return 0;
>  }
> 
> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
> +{
> +	const struct qmp_phy_cfg *cfg = qmp->cfg;
> +	int ret;
> +
> +	if (!cfg->no_pcs_sw_reset)
> +		return 0;
> +
> +	/*
> +	 * Get UFS reset, which is delayed until now to avoid a
> +	 * circular dependency where UFS needs its PHY, but the PHY
> +	 * needs this UFS reset.

This is invoked only once, from qcom_ufs_probe(), so it doesn't seem
accurate anymore. How come this is no longer needed? Please describe
what changed int he commit message.

> +	 */
> +	if (!qmp->ufs_reset) {
> +		qmp->ufs_reset =
> +		devm_reset_control_get_exclusive(qmp->dev, "ufsphy");

The line break here is really weird, are you sure checkpatch --strict
didn't complain about this one?

> +
> +		if (IS_ERR(qmp->ufs_reset)) {
> +			ret = PTR_ERR(qmp->ufs_reset);
> +			dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);

return dev_err_probe(qmp->dev, PTR_ERR(qmp->ufs_reset), "failed to...: %pe\n", qmp->ufs_reset);

While being more succinct, it also stores the reason for failing the
probe so that you can find it in /sys/kernel/debug/devices_deferred

> +			qmp->ufs_reset = NULL;

Use a local variable if you're worried about someone accessing the stale
error code after returning here.

Regards,
Bjorn

> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>  static int qmp_ufs_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> @@ -2114,6 +2106,10 @@ static int qmp_ufs_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
> 
> +	ret = qmp_ufs_get_phy_reset(qmp);
> +	if (ret)
> +		return ret;
> +
>  	/* Check for legacy binding with child node. */
>  	np = of_get_next_available_child(dev->of_node, NULL);
>  	if (np) {
> --
> 2.48.1
> 
> 

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Re: [PATCH V2 6/6] scsi: ufs: host : Introduce phy_power_on/off wrapper function

[Bjorn Andersson]

On Tue, Mar 18, 2025 at 08:19:44PM +0530, Nitin Rawat wrote:
> 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.
> 

Please describe the problem properly here. Are you introducing the mutex
because there is a problem, or because you want to be "safe"?

Why is it "refcounted", is the calling code paths no longer in sync? How
long has the current implementation been broken?

Regards,
Bjorn

> 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 5c7b6c75d669..8f80724e64b9 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);
> @@ -1017,7 +1049,6 @@ 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;
> 
>  	/*
> @@ -1037,7 +1068,7 @@ 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, "phy power off failed, ret=%d\n", err);
>  					return err;
> @@ -1046,7 +1077,7 @@ 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, "phy power on failed, ret = %d\n", err);
>  				return err;
> @@ -1233,10 +1264,9 @@ 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
> 
> 

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Re: [PATCH V2 3/6] phy: qcom-qmp-ufs: Refactor UFS PHY reset

[Nitin Rawat]

On 3/18/2025 8:43 PM, neil.armstrong@linaro.org wrote:
> On 18/03/2025 15:49, Nitin Rawat wrote:
>> Refactor the UFS PHY reset handling to parse the reset logic only once
>> during probe, instead of every resume.
>>
>> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
>> qmp_ufs_probe to avoid unnecessary parsing during resume.
>>
>> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
>> ---
>>   drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 104 ++++++++++++------------
>>   1 file changed, 50 insertions(+), 54 deletions(-)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/ 
>> qualcomm/phy-qcom-qmp-ufs.c
>> index 0089ee80f852..3a80c2c110d2 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> @@ -1757,32 +1757,6 @@ static void qmp_ufs_init_registers(struct 
>> qmp_ufs *qmp, const struct qmp_phy_cfg
>>       qmp_ufs_init_all(qmp, &cfg->tbls_hs_b);
>>   }
>>
>> -static int qmp_ufs_com_init(struct qmp_ufs *qmp)
>> -{
>> -    const struct qmp_phy_cfg *cfg = qmp->cfg;
>> -    void __iomem *pcs = qmp->pcs;
>> -    int ret;
>> -
>> -    ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
>> -    if (ret) {
>> -        dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
>> -        return ret;
>> -    }
>> -
>> -    ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
>> -    if (ret)
>> -        goto err_disable_regulators;
>> -
>> -    qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
>> -
>> -    return 0;
>> -
>> -err_disable_regulators:
>> -    regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
>> -
>> -    return ret;
>> -}
>> -
>>   static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
>>   {
>>       const struct qmp_phy_cfg *cfg = qmp->cfg;
>> @@ -1800,41 +1774,27 @@ static int qmp_ufs_power_on(struct phy *phy)
>>   {
>>       struct qmp_ufs *qmp = phy_get_drvdata(phy);
>>       const struct qmp_phy_cfg *cfg = qmp->cfg;
>> +    void __iomem *pcs = qmp->pcs;
>>       int ret;
>> -    dev_vdbg(qmp->dev, "Initializing QMP phy\n");
>> -
>> -    if (cfg->no_pcs_sw_reset) {
>> -        /*
>> -         * Get UFS reset, which is delayed until now to avoid a
>> -         * circular dependency where UFS needs its PHY, but the PHY
>> -         * needs this UFS reset.
>> -         */
>> -        if (!qmp->ufs_reset) {
>> -            qmp->ufs_reset =
>> -                devm_reset_control_get_exclusive(qmp->dev,
>> -                                 "ufsphy");
>> -
>> -            if (IS_ERR(qmp->ufs_reset)) {
>> -                ret = PTR_ERR(qmp->ufs_reset);
>> -                dev_err(qmp->dev,
>> -                    "failed to get UFS reset: %d\n",
>> -                    ret);
>> -
>> -                qmp->ufs_reset = NULL;
>> -                return ret;
>> -            }
>> -        }
>>
>> -        ret = reset_control_assert(qmp->ufs_reset);
>> -        if (ret)
>> -            return ret;
>> +    ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
>> +    if (ret) {
>> +        dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
>> +        return ret;
>>       }
>>
>> -    ret = qmp_ufs_com_init(qmp);
>> +    ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
>>       if (ret)
>> -        return ret;
>> +        goto err_disable_regulators;
>> +
>> +    qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
>>
>>       return 0;
>> +
>> +err_disable_regulators:
>> +    regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
>> +
>> +    return ret;
>>   }
> 
> This change is too fuzzy, please introduce qmp_ufs_get_phy_reset()
> in a patch, move qmp_ufs_com_init() inline in qmp_ufs_power_on()
> in a second time, and finally move reset_control_assert() to
> calibrate in a third patch (and explain why).

Thanks for the comment. I have taken care of this by separating 
qmp_ufs_get_phy_reset and inlining qmp_ufs_com_init in 2 separate patches.

Thanks,
Nitin

> 
> Thanks,
> Neil
> 
>>
>>   static int qmp_ufs_phy_calibrate(struct phy *phy)
>> @@ -1846,6 +1806,10 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
>>       unsigned int val;
>>       int ret;
>>
>> +    ret = reset_control_assert(qmp->ufs_reset);
>> +    if (ret)
>> +        return ret;
>> +
>>       qmp_ufs_init_registers(qmp, cfg);
>>
>>       ret = reset_control_deassert(qmp->ufs_reset);
>> @@ -2088,6 +2052,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
>>       return 0;
>>   }
>>
>> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
>> +{
>> +    const struct qmp_phy_cfg *cfg = qmp->cfg;
>> +    int ret;
>> +
>> +    if (!cfg->no_pcs_sw_reset)
>> +        return 0;
>> +
>> +    /*
>> +     * Get UFS reset, which is delayed until now to avoid a
>> +     * circular dependency where UFS needs its PHY, but the PHY
>> +     * needs this UFS reset.
>> +     */
>> +    if (!qmp->ufs_reset) {
>> +        qmp->ufs_reset =
>> +        devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
>> +
>> +        if (IS_ERR(qmp->ufs_reset)) {
>> +            ret = PTR_ERR(qmp->ufs_reset);
>> +            dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
>> +            qmp->ufs_reset = NULL;
>> +            return ret;
>> +        }
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>>   static int qmp_ufs_probe(struct platform_device *pdev)
>>   {
>>       struct device *dev = &pdev->dev;
>> @@ -2114,6 +2106,10 @@ static int qmp_ufs_probe(struct platform_device 
>> *pdev)
>>       if (ret)
>>           return ret;
>>
>> +    ret = qmp_ufs_get_phy_reset(qmp);
>> +    if (ret)
>> +        return ret;
>> +
>>       /* Check for legacy binding with child node. */
>>       np = of_get_next_available_child(dev->of_node, NULL);
>>       if (np) {
>> -- 
>> 2.48.1
>>
>>
> 


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Re: [PATCH V2 2/6] phy: qcom-qmp-ufs: Refactor phy_power_on and phy_calibrate callbacks

[Nitin Rawat]

On 3/18/2025 8:39 PM, neil.armstrong@linaro.org wrote:
> On 18/03/2025 15:49, Nitin Rawat wrote:
>> Commit 052553af6a31 ("ufs/phy: qcom: Refactor to use phy_init call")
>> puts enabling regulators & clks, calibrating UFS PHY, starting serdes
>> and polling PCS ready status into phy_power_on.
>>
>> In Current code regulators enable, clks enable, calibrating UFS PHY,
>> start_serdes and polling PCS_ready_status are part of phy_power_on.
>>
>> UFS PHY registers are retained after power collapse, meaning calibrating
>> UFS PHY, start_serdes and polling PCS_ready_status can be done only when
>> hba is powered_on, and not needed every time when phy_power_on is called
>> during resume. Hence keep the code which enables PHY's regulators & clks
>> in phy_power_on and move the rest steps into phy_calibrate function.
>>
>> Refactor the code to retain PHY regulators & clks in phy_power_on and
>> move out rest of the code to new phy_calibrate function.
>>
>> 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/phy/qualcomm/phy-qcom-qmp-ufs.c | 18 ++----------------
>>   1 file changed, 2 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/ 
>> qualcomm/phy-qcom-qmp-ufs.c
>> index bb836bc0f736..0089ee80f852 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> @@ -1796,7 +1796,7 @@ static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
>>       return 0;
>>   }
>>
>> -static int qmp_ufs_init(struct phy *phy)
>> +static int qmp_ufs_power_on(struct phy *phy)
>>   {
>>       struct qmp_ufs *qmp = phy_get_drvdata(phy);
>>       const struct qmp_phy_cfg *cfg = qmp->cfg;
>> @@ -1898,21 +1898,6 @@ static int qmp_ufs_exit(struct phy *phy)
>>       return 0;
>>   }
>>
>> -static int qmp_ufs_power_on(struct phy *phy)
>> -{
>> -    int ret;
>> -
>> -    ret = qmp_ufs_init(phy);
>> -    if (ret)
>> -        return ret;
>> -
>> -    ret = qmp_ufs_phy_calibrate(phy);
>> -    if (ret)
>> -        qmp_ufs_exit(phy);
>> -
>> -    return ret;
>> -}
>> -
>>   static int qmp_ufs_disable(struct phy *phy)
>>   {
>>       int ret;
>> @@ -1942,6 +1927,7 @@ static int qmp_ufs_set_mode(struct phy *phy, 
>> enum phy_mode mode, int submode)
>>   static const struct phy_ops qcom_qmp_ufs_phy_ops = {
>>       .power_on    = qmp_ufs_power_on,
>>       .power_off    = qmp_ufs_disable,
>> +    .calibrate    = qmp_ufs_phy_calibrate,
> 
> Ok so this will break the UFS until patch 5 is applied,
> breaking bisectability.
> 
> Make sure UFS host driver calls calibrate first, and then
> do the refactor in the PHY driver.

Hi Neil.

Thanks for the review. I have taken care of bisecatablity
compliance by making UFS host driver calls calibrate first
in latest patch set.

Regards,
Nitin



> 
> And either all would go in a single tree or either PHY
> or SCSI maintainer would need to provide an immutable
> branch for the final merge.
> 
>>       .set_mode    = qmp_ufs_set_mode,
>>       .owner        = THIS_MODULE,
>>   };
>> -- 
>> 2.48.1
>>
>>
> 


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Re: [PATCH V2 3/6] phy: qcom-qmp-ufs: Refactor UFS PHY reset

[Nitin Rawat]

On 3/19/2025 1:16 AM, Bjorn Andersson wrote:
> On Tue, Mar 18, 2025 at 08:19:41PM +0530, Nitin Rawat wrote:
>> Refactor the UFS PHY reset handling to parse the reset logic only once
>> during probe, instead of every resume.
>>
> 
> This looks very reasonable! But it would be preferred to see the commit
> messages following the what format outlines in
> https://docs.kernel.org/process/submitting-patches.html#describe-your-changes
> with a clear problem description followed by a description of the
> technical solution.
> 
>> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
>> qmp_ufs_probe to avoid unnecessary parsing during resume.
> 
> Please add ()-suffix to function names in your commit messages.
> 
> Also, this series moves things around a lot, can you confirm that UFS is
> working inbetween each one of this patches, so that the branch is
> bisectable when this is being picked up?

Hi Bjorn,

Thanks for the review. I've addressed the bisectability compliance in my 
latest patch set (patchset #3) that I posted today. I just realized I 
missed your other comments about adding the ()-suffix to function names 
in commit messages. Sorry about that. I'll make sure to include this in 
my next patch set.

Thanks,
Nitin


> 
>>
>> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
>> ---
>>   drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 104 ++++++++++++------------
>>   1 file changed, 50 insertions(+), 54 deletions(-)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> index 0089ee80f852..3a80c2c110d2 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> @@ -1757,32 +1757,6 @@ static void qmp_ufs_init_registers(struct qmp_ufs *qmp, const struct qmp_phy_cfg
>>   	qmp_ufs_init_all(qmp, &cfg->tbls_hs_b);
>>   }
>>
>> -static int qmp_ufs_com_init(struct qmp_ufs *qmp)
>> -{
>> -	const struct qmp_phy_cfg *cfg = qmp->cfg;
>> -	void __iomem *pcs = qmp->pcs;
>> -	int ret;
>> -
>> -	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
>> -	if (ret) {
>> -		dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
>> -		return ret;
>> -	}
>> -
>> -	ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
>> -	if (ret)
>> -		goto err_disable_regulators;
>> -
>> -	qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
>> -
>> -	return 0;
>> -
>> -err_disable_regulators:
>> -	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
>> -
>> -	return ret;
>> -}
>> -
>>   static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
>>   {
>>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
>> @@ -1800,41 +1774,27 @@ static int qmp_ufs_power_on(struct phy *phy)
>>   {
>>   	struct qmp_ufs *qmp = phy_get_drvdata(phy);
>>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
>> +	void __iomem *pcs = qmp->pcs;
> 
> This is only used once, perhaps not worth a local variable to save 5
> characters on that line?
> 
>>   	int ret;
>> -	dev_vdbg(qmp->dev, "Initializing QMP phy\n");
>> -
>> -	if (cfg->no_pcs_sw_reset) {
>> -		/*
>> -		 * Get UFS reset, which is delayed until now to avoid a
>> -		 * circular dependency where UFS needs its PHY, but the PHY
>> -		 * needs this UFS reset.
>> -		 */
>> -		if (!qmp->ufs_reset) {
>> -			qmp->ufs_reset =
>> -				devm_reset_control_get_exclusive(qmp->dev,
>> -								 "ufsphy");
>> -
>> -			if (IS_ERR(qmp->ufs_reset)) {
>> -				ret = PTR_ERR(qmp->ufs_reset);
>> -				dev_err(qmp->dev,
>> -					"failed to get UFS reset: %d\n",
>> -					ret);
>> -
>> -				qmp->ufs_reset = NULL;
>> -				return ret;
>> -			}
>> -		}
>>
>> -		ret = reset_control_assert(qmp->ufs_reset);
>> -		if (ret)
>> -			return ret;
>> +	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
>> +	if (ret) {
>> +		dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
> 
> regulator_bulk_enable() will already have printed a more useful error
> message, letting you know which of the vregs[] it was that failed to
> enable.
> 
>> +		return ret;
>>   	}
>>
>> -	ret = qmp_ufs_com_init(qmp);
>> +	ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
>>   	if (ret)
>> -		return ret;
>> +		goto err_disable_regulators;
>> +
>> +	qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
>>
>>   	return 0;
>> +
>> +err_disable_regulators:
>> +	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
>> +
>> +	return ret;
>>   }
>>
>>   static int qmp_ufs_phy_calibrate(struct phy *phy)
>> @@ -1846,6 +1806,10 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
>>   	unsigned int val;
>>   	int ret;
>>
>> +	ret = reset_control_assert(qmp->ufs_reset);
>> +	if (ret)
>> +		return ret;
>> +
>>   	qmp_ufs_init_registers(qmp, cfg);
>>
>>   	ret = reset_control_deassert(qmp->ufs_reset);
>> @@ -2088,6 +2052,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
>>   	return 0;
>>   }
>>
>> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
>> +{
>> +	const struct qmp_phy_cfg *cfg = qmp->cfg;
>> +	int ret;
>> +
>> +	if (!cfg->no_pcs_sw_reset)
>> +		return 0;
>> +
>> +	/*
>> +	 * Get UFS reset, which is delayed until now to avoid a
>> +	 * circular dependency where UFS needs its PHY, but the PHY
>> +	 * needs this UFS reset.
> 
> This is invoked only once, from qcom_ufs_probe(), so it doesn't seem
> accurate anymore. How come this is no longer needed? Please describe
> what changed int he commit message.
> 
>> +	 */
>> +	if (!qmp->ufs_reset) {
>> +		qmp->ufs_reset =
>> +		devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
> 
> The line break here is really weird, are you sure checkpatch --strict
> didn't complain about this one?
> 
>> +
>> +		if (IS_ERR(qmp->ufs_reset)) {
>> +			ret = PTR_ERR(qmp->ufs_reset);
>> +			dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
> 
> return dev_err_probe(qmp->dev, PTR_ERR(qmp->ufs_reset), "failed to...: %pe\n", qmp->ufs_reset);
> 
> While being more succinct, it also stores the reason for failing the
> probe so that you can find it in /sys/kernel/debug/devices_deferred
> 
>> +			qmp->ufs_reset = NULL;
> 
> Use a local variable if you're worried about someone accessing the stale
> error code after returning here.
> 
> Regards,
> Bjorn
> 
>> +			return ret;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>   static int qmp_ufs_probe(struct platform_device *pdev)
>>   {
>>   	struct device *dev = &pdev->dev;
>> @@ -2114,6 +2106,10 @@ static int qmp_ufs_probe(struct platform_device *pdev)
>>   	if (ret)
>>   		return ret;
>>
>> +	ret = qmp_ufs_get_phy_reset(qmp);
>> +	if (ret)
>> +		return ret;
>> +
>>   	/* Check for legacy binding with child node. */
>>   	np = of_get_next_available_child(dev->of_node, NULL);
>>   	if (np) {
>> --
>> 2.48.1
>>
>>


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Re: [PATCH V2 6/6] scsi: ufs: host : Introduce phy_power_on/off wrapper function

[Nitin Rawat]

On 3/19/2025 1:20 AM, Bjorn Andersson wrote:
> On Tue, Mar 18, 2025 at 08:19:44PM +0530, Nitin Rawat wrote:
>> 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.
>>
> 
> Please describe the problem properly here. Are you introducing the mutex
> because there is a problem, or because you want to be "safe"?
> 
> Why is it "refcounted", is the calling code paths no longer in sync? How
> long has the current implementation been broken?
> 
> Regards,
> Bjorn
> 

Hi Bjorn,

Thanks for the review. There are scenarios where ufshcd_link_startup() 
can call ufshcd_vops_link_startup_notify() multiple times during 
retries. This leads to the PHY reference count increasing continuously, 
preventing proper re-initialization of the PHY.

Recently, this issue was addressed with patch 7bac65687510 ("scsi: ufs: 
qcom: Power off the PHY if it was already powered on in 
ufs_qcom_power_up_sequence()"). However, I still want to maintain a 
reference count (ref_cnt) to safeguard against similar conditions in the 
code. Additionally, this approach helps avoid unnecessary phy_power_on 
and phy_power_off calls. Please let me know your thoughts.

Regrads,
Nitin




>> 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 5c7b6c75d669..8f80724e64b9 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);
>> @@ -1017,7 +1049,6 @@ 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;
>>
>>   	/*
>> @@ -1037,7 +1068,7 @@ 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, "phy power off failed, ret=%d\n", err);
>>   					return err;
>> @@ -1046,7 +1077,7 @@ 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, "phy power on failed, ret = %d\n", err);
>>   				return err;
>> @@ -1233,10 +1264,9 @@ 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
>>
>>


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Re: [PATCH V2 2/6] phy: qcom-qmp-ufs: Refactor phy_power_on and phy_calibrate callbacks

[Dmitry Baryshkov]

On Thu, Apr 10, 2025 at 02:43:52PM +0530, Nitin Rawat wrote:
> 
> 
> On 3/18/2025 8:39 PM, neil.armstrong@linaro.org wrote:
> > On 18/03/2025 15:49, Nitin Rawat wrote:
> > > Commit 052553af6a31 ("ufs/phy: qcom: Refactor to use phy_init call")
> > > puts enabling regulators & clks, calibrating UFS PHY, starting serdes
> > > and polling PCS ready status into phy_power_on.
> > > 
> > > In Current code regulators enable, clks enable, calibrating UFS PHY,
> > > start_serdes and polling PCS_ready_status are part of phy_power_on.
> > > 
> > > UFS PHY registers are retained after power collapse, meaning calibrating
> > > UFS PHY, start_serdes and polling PCS_ready_status can be done only when
> > > hba is powered_on, and not needed every time when phy_power_on is called
> > > during resume. Hence keep the code which enables PHY's regulators & clks
> > > in phy_power_on and move the rest steps into phy_calibrate function.
> > > 
> > > Refactor the code to retain PHY regulators & clks in phy_power_on and
> > > move out rest of the code to new phy_calibrate function.
> > > 
> > > 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/phy/qualcomm/phy-qcom-qmp-ufs.c | 18 ++----------------
> > >   1 file changed, 2 insertions(+), 16 deletions(-)
> > > 
> > > diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/
> > > qualcomm/phy-qcom-qmp-ufs.c
> > > index bb836bc0f736..0089ee80f852 100644
> > > --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> > > +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> > > @@ -1796,7 +1796,7 @@ static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
> > >       return 0;
> > >   }
> > > 
> > > -static int qmp_ufs_init(struct phy *phy)
> > > +static int qmp_ufs_power_on(struct phy *phy)
> > >   {
> > >       struct qmp_ufs *qmp = phy_get_drvdata(phy);
> > >       const struct qmp_phy_cfg *cfg = qmp->cfg;
> > > @@ -1898,21 +1898,6 @@ static int qmp_ufs_exit(struct phy *phy)
> > >       return 0;
> > >   }
> > > 
> > > -static int qmp_ufs_power_on(struct phy *phy)
> > > -{
> > > -    int ret;
> > > -
> > > -    ret = qmp_ufs_init(phy);
> > > -    if (ret)
> > > -        return ret;
> > > -
> > > -    ret = qmp_ufs_phy_calibrate(phy);
> > > -    if (ret)
> > > -        qmp_ufs_exit(phy);
> > > -
> > > -    return ret;
> > > -}
> > > -
> > >   static int qmp_ufs_disable(struct phy *phy)
> > >   {
> > >       int ret;
> > > @@ -1942,6 +1927,7 @@ static int qmp_ufs_set_mode(struct phy *phy,
> > > enum phy_mode mode, int submode)
> > >   static const struct phy_ops qcom_qmp_ufs_phy_ops = {
> > >       .power_on    = qmp_ufs_power_on,
> > >       .power_off    = qmp_ufs_disable,
> > > +    .calibrate    = qmp_ufs_phy_calibrate,
> > 
> > Ok so this will break the UFS until patch 5 is applied,
> > breaking bisectability.
> > 
> > Make sure UFS host driver calls calibrate first, and then
> > do the refactor in the PHY driver.
> 
> Hi Neil.
> 
> Thanks for the review. I have taken care of bisecatablity
> compliance by making UFS host driver calls calibrate first
> in latest patch set.

_latest_. So if this patch gets merged first, UFS support will be
broken.

> 
> Regards,
> Nitin
> 
> 
> 
> > 
> > And either all would go in a single tree or either PHY
> > or SCSI maintainer would need to provide an immutable
> > branch for the final merge.
> > 
> > >       .set_mode    = qmp_ufs_set_mode,
> > >       .owner        = THIS_MODULE,
> > >   };
> > > -- 
> > > 2.48.1
> > > 
> > > 
> > 
> 

-- 
With best wishes
Dmitry

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