[PATCH RESEND v3 0/5] phy: renesas: rcar-gen3-usb2: Fixes for Renesas RZ/G3S

[PATCH RESEND v3 0/5] phy: renesas: rcar-gen3-usb2: Fixes for Renesas RZ/G3S

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

Hi,

Series add fixes for the Renesas USB2 PHY driver identified while
working on the Renesas RZ/G3S USB support. These changes are
needed for the upcomming RZ/G3S USB support (especially for the
power management support).

Series (with [1] on top) was tested on Renesas RZ/G3S with consecutive
unbind/bind and data transfer tests before/after the unbind/bind.

The unbind/bind was also tested on the devices with the following
device trees but w/o checking the data transfer (as I only had
remote access w/o USB devices connected):
- r8a7742-iwg21d-q7.dts
- r8a7743-iwg20d-q7.dts
- r8a7744-iwg20d-q7.dts
- r8a7745-iwg22d-sodimm.dts
- r8a77470-iwg23s-sbc.dts
- r8a774a1-hihope-rzg2m-ex.dts
- r8a774b1-hihope-rzg2n-ex.dts
- r8a774e1-hihope-rzg2h-ex.dts
- r9a07g043u11-smarc.dts
- r9a07g044c2-smarc.dts
- r9a07g044l2-smarc.dts
- r9a07g054l2-smarc.dts
- r9a07g043f01-smarc.dts

Thank you,
Claudiu Beznea

Changes in v3:
- collected tags
- improve the validation on the code that requests the
  optional IRQ as suggested in the review process

Changes in v2:
- dropped RFT
- collected tags
- fixed checkpatch.pl warnings

[1] https://lore.kernel.org/all/20250219161239.1751756-1-claudiu.beznea.uj@bp.renesas.com/

Claudiu Beznea (5):
  phy: renesas: rcar-gen3-usb2: Fix role detection on unbind/bind
  phy: renesas: rcar-gen3-usb2: Move IRQ request in probe
  phy: renesas: rcar-gen3-usb2: Lock around hardware registers and
    driver data
  phy: renesas: rcar-gen3-usb2: Assert PLL reset on PHY power off
  phy: renesas: rcar-gen3-usb2: Set timing registers only once

 drivers/phy/renesas/phy-rcar-gen3-usb2.c | 135 +++++++++++++----------
 1 file changed, 75 insertions(+), 60 deletions(-)

-- 
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[PATCH RESEND v3 1/5] phy: renesas: rcar-gen3-usb2: Fix role detection on unbind/bind

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

It has been observed on the Renesas RZ/G3S SoC that unbinding and binding
the PHY driver leads to role autodetection failures. This issue occurs when
PHY 3 is the first initialized PHY. PHY 3 does not have an interrupt
associated with the USB2_INT_ENABLE register (as
rcar_gen3_int_enable[3] = 0). As a result, rcar_gen3_init_otg() is called
to initialize OTG without enabling PHY interrupts.

To resolve this, add rcar_gen3_is_any_otg_rphy_initialized() and call it in
role_store(), role_show(), and rcar_gen3_init_otg(). At the same time,
rcar_gen3_init_otg() is only called when initialization for a PHY with
interrupt bits is in progress. As a result, the
struct rcar_gen3_phy::otg_initialized is no longer needed.

Fixes: 549b6b55b005 ("phy: renesas: rcar-gen3-usb2: enable/disable independent irqs")
Cc: stable@vger.kernel.org
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v3:
- collected tags

Changes in v2:
- collected tags

 drivers/phy/renesas/phy-rcar-gen3-usb2.c | 33 ++++++++++--------------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
index 775f4f973a6c..46afba2fe0dc 100644
--- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
+++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
@@ -107,7 +107,6 @@ struct rcar_gen3_phy {
 	struct rcar_gen3_chan *ch;
 	u32 int_enable_bits;
 	bool initialized;
-	bool otg_initialized;
 	bool powered;
 };
 
@@ -320,16 +319,15 @@ static bool rcar_gen3_is_any_rphy_initialized(struct rcar_gen3_chan *ch)
 	return false;
 }
 
-static bool rcar_gen3_needs_init_otg(struct rcar_gen3_chan *ch)
+static bool rcar_gen3_is_any_otg_rphy_initialized(struct rcar_gen3_chan *ch)
 {
-	int i;
-
-	for (i = 0; i < NUM_OF_PHYS; i++) {
-		if (ch->rphys[i].otg_initialized)
-			return false;
+	for (enum rcar_gen3_phy_index i = PHY_INDEX_BOTH_HC; i <= PHY_INDEX_EHCI;
+	     i++) {
+		if (ch->rphys[i].initialized)
+			return true;
 	}
 
-	return true;
+	return false;
 }
 
 static bool rcar_gen3_are_all_rphys_power_off(struct rcar_gen3_chan *ch)
@@ -351,7 +349,7 @@ static ssize_t role_store(struct device *dev, struct device_attribute *attr,
 	bool is_b_device;
 	enum phy_mode cur_mode, new_mode;
 
-	if (!ch->is_otg_channel || !rcar_gen3_is_any_rphy_initialized(ch))
+	if (!ch->is_otg_channel || !rcar_gen3_is_any_otg_rphy_initialized(ch))
 		return -EIO;
 
 	if (sysfs_streq(buf, "host"))
@@ -389,7 +387,7 @@ static ssize_t role_show(struct device *dev, struct device_attribute *attr,
 {
 	struct rcar_gen3_chan *ch = dev_get_drvdata(dev);
 
-	if (!ch->is_otg_channel || !rcar_gen3_is_any_rphy_initialized(ch))
+	if (!ch->is_otg_channel || !rcar_gen3_is_any_otg_rphy_initialized(ch))
 		return -EIO;
 
 	return sprintf(buf, "%s\n", rcar_gen3_is_host(ch) ? "host" :
@@ -402,6 +400,9 @@ static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
 	void __iomem *usb2_base = ch->base;
 	u32 val;
 
+	if (!ch->is_otg_channel || rcar_gen3_is_any_otg_rphy_initialized(ch))
+		return;
+
 	/* Should not use functions of read-modify-write a register */
 	val = readl(usb2_base + USB2_LINECTRL1);
 	val = (val & ~USB2_LINECTRL1_DP_RPD) | USB2_LINECTRL1_DPRPD_EN |
@@ -465,12 +466,9 @@ static int rcar_gen3_phy_usb2_init(struct phy *p)
 	writel(USB2_SPD_RSM_TIMSET_INIT, usb2_base + USB2_SPD_RSM_TIMSET);
 	writel(USB2_OC_TIMSET_INIT, usb2_base + USB2_OC_TIMSET);
 
-	/* Initialize otg part */
-	if (channel->is_otg_channel) {
-		if (rcar_gen3_needs_init_otg(channel))
-			rcar_gen3_init_otg(channel);
-		rphy->otg_initialized = true;
-	}
+	/* Initialize otg part (only if we initialize a PHY with IRQs). */
+	if (rphy->int_enable_bits)
+		rcar_gen3_init_otg(channel);
 
 	rphy->initialized = true;
 
@@ -486,9 +484,6 @@ static int rcar_gen3_phy_usb2_exit(struct phy *p)
 
 	rphy->initialized = false;
 
-	if (channel->is_otg_channel)
-		rphy->otg_initialized = false;
-
 	val = readl(usb2_base + USB2_INT_ENABLE);
 	val &= ~rphy->int_enable_bits;
 	if (!rcar_gen3_is_any_rphy_initialized(channel))
-- 
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[PATCH RESEND v3 2/5] phy: renesas: rcar-gen3-usb2: Move IRQ request in probe

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

Commit 08b0ad375ca6 ("phy: renesas: rcar-gen3-usb2: move IRQ registration
to init") moved the IRQ request operation from probe to
struct phy_ops::phy_init API to avoid triggering interrupts (which lead to
register accesses) while the PHY clocks (enabled through runtime PM APIs)
are not active. If this happens, it results in a synchronous abort.

One way to reproduce this issue is by enabling CONFIG_DEBUG_SHIRQ, which
calls free_irq() on driver removal.

Move the IRQ request and free operations back to probe, and take the
runtime PM state into account in IRQ handler. This commit is preparatory
for the subsequent fixes in this series.

Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v3:
- collected tags
- improve the validation on the value returned by
  platform_get_irq_optional()

Changes in v2:
- collected tags

 drivers/phy/renesas/phy-rcar-gen3-usb2.c | 46 +++++++++++++-----------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
index 46afba2fe0dc..bb05fd26eb7f 100644
--- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
+++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
@@ -120,7 +120,6 @@ struct rcar_gen3_chan {
 	struct work_struct work;
 	struct mutex lock;	/* protects rphys[...].powered */
 	enum usb_dr_mode dr_mode;
-	int irq;
 	u32 obint_enable_bits;
 	bool extcon_host;
 	bool is_otg_channel;
@@ -428,16 +427,25 @@ static irqreturn_t rcar_gen3_phy_usb2_irq(int irq, void *_ch)
 {
 	struct rcar_gen3_chan *ch = _ch;
 	void __iomem *usb2_base = ch->base;
-	u32 status = readl(usb2_base + USB2_OBINTSTA);
+	struct device *dev = ch->dev;
 	irqreturn_t ret = IRQ_NONE;
+	u32 status;
 
+	pm_runtime_get_noresume(dev);
+
+	if (pm_runtime_suspended(dev))
+		goto rpm_put;
+
+	status = readl(usb2_base + USB2_OBINTSTA);
 	if (status & ch->obint_enable_bits) {
-		dev_vdbg(ch->dev, "%s: %08x\n", __func__, status);
+		dev_vdbg(dev, "%s: %08x\n", __func__, status);
 		writel(ch->obint_enable_bits, usb2_base + USB2_OBINTSTA);
 		rcar_gen3_device_recognition(ch);
 		ret = IRQ_HANDLED;
 	}
 
+rpm_put:
+	pm_runtime_put_noidle(dev);
 	return ret;
 }
 
@@ -447,17 +455,6 @@ static int rcar_gen3_phy_usb2_init(struct phy *p)
 	struct rcar_gen3_chan *channel = rphy->ch;
 	void __iomem *usb2_base = channel->base;
 	u32 val;
-	int ret;
-
-	if (!rcar_gen3_is_any_rphy_initialized(channel) && channel->irq >= 0) {
-		INIT_WORK(&channel->work, rcar_gen3_phy_usb2_work);
-		ret = request_irq(channel->irq, rcar_gen3_phy_usb2_irq,
-				  IRQF_SHARED, dev_name(channel->dev), channel);
-		if (ret < 0) {
-			dev_err(channel->dev, "No irq handler (%d)\n", channel->irq);
-			return ret;
-		}
-	}
 
 	/* Initialize USB2 part */
 	val = readl(usb2_base + USB2_INT_ENABLE);
@@ -490,9 +487,6 @@ static int rcar_gen3_phy_usb2_exit(struct phy *p)
 		val &= ~USB2_INT_ENABLE_UCOM_INTEN;
 	writel(val, usb2_base + USB2_INT_ENABLE);
 
-	if (channel->irq >= 0 && !rcar_gen3_is_any_rphy_initialized(channel))
-		free_irq(channel->irq, channel);
-
 	return 0;
 }
 
@@ -698,7 +692,7 @@ static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct rcar_gen3_chan *channel;
 	struct phy_provider *provider;
-	int ret = 0, i;
+	int ret = 0, i, irq;
 
 	if (!dev->of_node) {
 		dev_err(dev, "This driver needs device tree\n");
@@ -714,8 +708,6 @@ static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
 		return PTR_ERR(channel->base);
 
 	channel->obint_enable_bits = USB2_OBINT_BITS;
-	/* get irq number here and request_irq for OTG in phy_init */
-	channel->irq = platform_get_irq_optional(pdev, 0);
 	channel->dr_mode = rcar_gen3_get_dr_mode(dev->of_node);
 	if (channel->dr_mode != USB_DR_MODE_UNKNOWN) {
 		channel->is_otg_channel = true;
@@ -784,6 +776,20 @@ static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
 		channel->vbus = NULL;
 	}
 
+	irq = platform_get_irq_optional(pdev, 0);
+	if (irq < 0 && irq != -ENXIO) {
+		ret = irq;
+		goto error;
+	} else if (irq > 0) {
+		INIT_WORK(&channel->work, rcar_gen3_phy_usb2_work);
+		ret = devm_request_irq(dev, irq, rcar_gen3_phy_usb2_irq,
+				       IRQF_SHARED, dev_name(dev), channel);
+		if (ret < 0) {
+			dev_err(dev, "Failed to request irq (%d)\n", irq);
+			goto error;
+		}
+	}
+
 	provider = devm_of_phy_provider_register(dev, rcar_gen3_phy_usb2_xlate);
 	if (IS_ERR(provider)) {
 		dev_err(dev, "Failed to register PHY provider\n");
-- 
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[PATCH RESEND v3 3/5] phy: renesas: rcar-gen3-usb2: Lock around hardware registers and driver data

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

The phy-rcar-gen3-usb2 driver exposes four individual PHYs that are
requested and configured by PHY users. The struct phy_ops APIs access the
same set of registers to configure all PHYs. Additionally, PHY settings can
be modified through sysfs or an IRQ handler. While some struct phy_ops APIs
are protected by a driver-wide mutex, others rely on individual
PHY-specific mutexes.

This approach can lead to various issues, including:
1/ the IRQ handler may interrupt PHY settings in progress, racing with
   hardware configuration protected by a mutex lock
2/ due to msleep(20) in rcar_gen3_init_otg(), while a configuration thread
   suspends to wait for the delay, another thread may try to configure
   another PHY (with phy_init() + phy_power_on()); re-running the
   phy_init() goes to the exact same configuration code, re-running the
   same hardware configuration on the same set of registers (and bits)
   which might impact the result of the msleep for the 1st configuring
   thread
3/ sysfs can configure the hardware (though role_store()) and it can
   still race with the phy_init()/phy_power_on() APIs calling into the
   drivers struct phy_ops

To address these issues, add a spinlock to protect hardware register access
and driver private data structures (e.g., calls to
rcar_gen3_is_any_rphy_initialized()). Checking driver-specific data remains
necessary as all PHY instances share common settings. With this change,
the existing mutex protection is removed and the cleanup.h helpers are
used.

While at it, to keep the code simpler, do not skip
regulator_enable()/regulator_disable() APIs in
rcar_gen3_phy_usb2_power_on()/rcar_gen3_phy_usb2_power_off() as the
regulators enable/disable operations are reference counted anyway.

Fixes: f3b5a8d9b50d ("phy: rcar-gen3-usb2: Add R-Car Gen3 USB2 PHY driver")
Cc: stable@vger.kernel.org
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v3:
- collected tags

Changes in v2:
- collected tags

 drivers/phy/renesas/phy-rcar-gen3-usb2.c | 49 +++++++++++++-----------
 1 file changed, 26 insertions(+), 23 deletions(-)

diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
index bb05fd26eb7f..00ce564463de 100644
--- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
+++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
@@ -9,6 +9,7 @@
  * Copyright (C) 2014 Cogent Embedded, Inc.
  */
 
+#include <linux/cleanup.h>
 #include <linux/extcon-provider.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -118,7 +119,7 @@ struct rcar_gen3_chan {
 	struct regulator *vbus;
 	struct reset_control *rstc;
 	struct work_struct work;
-	struct mutex lock;	/* protects rphys[...].powered */
+	spinlock_t lock;	/* protects access to hardware and driver data structure. */
 	enum usb_dr_mode dr_mode;
 	u32 obint_enable_bits;
 	bool extcon_host;
@@ -348,6 +349,8 @@ static ssize_t role_store(struct device *dev, struct device_attribute *attr,
 	bool is_b_device;
 	enum phy_mode cur_mode, new_mode;
 
+	guard(spinlock_irqsave)(&ch->lock);
+
 	if (!ch->is_otg_channel || !rcar_gen3_is_any_otg_rphy_initialized(ch))
 		return -EIO;
 
@@ -415,7 +418,7 @@ static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
 		val = readl(usb2_base + USB2_ADPCTRL);
 		writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);
 	}
-	msleep(20);
+	mdelay(20);
 
 	writel(0xffffffff, usb2_base + USB2_OBINTSTA);
 	writel(ch->obint_enable_bits, usb2_base + USB2_OBINTEN);
@@ -436,12 +439,14 @@ static irqreturn_t rcar_gen3_phy_usb2_irq(int irq, void *_ch)
 	if (pm_runtime_suspended(dev))
 		goto rpm_put;
 
-	status = readl(usb2_base + USB2_OBINTSTA);
-	if (status & ch->obint_enable_bits) {
-		dev_vdbg(dev, "%s: %08x\n", __func__, status);
-		writel(ch->obint_enable_bits, usb2_base + USB2_OBINTSTA);
-		rcar_gen3_device_recognition(ch);
-		ret = IRQ_HANDLED;
+	scoped_guard(spinlock, &ch->lock) {
+		status = readl(usb2_base + USB2_OBINTSTA);
+		if (status & ch->obint_enable_bits) {
+			dev_vdbg(dev, "%s: %08x\n", __func__, status);
+			writel(ch->obint_enable_bits, usb2_base + USB2_OBINTSTA);
+			rcar_gen3_device_recognition(ch);
+			ret = IRQ_HANDLED;
+		}
 	}
 
 rpm_put:
@@ -456,6 +461,8 @@ static int rcar_gen3_phy_usb2_init(struct phy *p)
 	void __iomem *usb2_base = channel->base;
 	u32 val;
 
+	guard(spinlock_irqsave)(&channel->lock);
+
 	/* Initialize USB2 part */
 	val = readl(usb2_base + USB2_INT_ENABLE);
 	val |= USB2_INT_ENABLE_UCOM_INTEN | rphy->int_enable_bits;
@@ -479,6 +486,8 @@ static int rcar_gen3_phy_usb2_exit(struct phy *p)
 	void __iomem *usb2_base = channel->base;
 	u32 val;
 
+	guard(spinlock_irqsave)(&channel->lock);
+
 	rphy->initialized = false;
 
 	val = readl(usb2_base + USB2_INT_ENABLE);
@@ -498,16 +507,17 @@ static int rcar_gen3_phy_usb2_power_on(struct phy *p)
 	u32 val;
 	int ret = 0;
 
-	mutex_lock(&channel->lock);
-	if (!rcar_gen3_are_all_rphys_power_off(channel))
-		goto out;
-
 	if (channel->vbus) {
 		ret = regulator_enable(channel->vbus);
 		if (ret)
-			goto out;
+			return ret;
 	}
 
+	guard(spinlock_irqsave)(&channel->lock);
+
+	if (!rcar_gen3_are_all_rphys_power_off(channel))
+		goto out;
+
 	val = readl(usb2_base + USB2_USBCTR);
 	val |= USB2_USBCTR_PLL_RST;
 	writel(val, usb2_base + USB2_USBCTR);
@@ -517,7 +527,6 @@ static int rcar_gen3_phy_usb2_power_on(struct phy *p)
 out:
 	/* The powered flag should be set for any other phys anyway */
 	rphy->powered = true;
-	mutex_unlock(&channel->lock);
 
 	return 0;
 }
@@ -528,18 +537,12 @@ static int rcar_gen3_phy_usb2_power_off(struct phy *p)
 	struct rcar_gen3_chan *channel = rphy->ch;
 	int ret = 0;
 
-	mutex_lock(&channel->lock);
-	rphy->powered = false;
-
-	if (!rcar_gen3_are_all_rphys_power_off(channel))
-		goto out;
+	scoped_guard(spinlock_irqsave, &channel->lock)
+		rphy->powered = false;
 
 	if (channel->vbus)
 		ret = regulator_disable(channel->vbus);
 
-out:
-	mutex_unlock(&channel->lock);
-
 	return ret;
 }
 
@@ -750,7 +753,7 @@ static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
 	if (phy_data->no_adp_ctrl)
 		channel->obint_enable_bits = USB2_OBINT_IDCHG_EN;
 
-	mutex_init(&channel->lock);
+	spin_lock_init(&channel->lock);
 	for (i = 0; i < NUM_OF_PHYS; i++) {
 		channel->rphys[i].phy = devm_phy_create(dev, NULL,
 							phy_data->phy_usb2_ops);
-- 
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Re: [PATCH RESEND v3 3/5] phy: renesas: rcar-gen3-usb2: Lock around hardware registers and driver data

[Xia Fukun]

On 5/7/2025 8:50 PM, Claudiu wrote:

> @@ -348,6 +349,8 @@ static ssize_t role_store(struct device *dev, struct device_attribute *attr,
>  	bool is_b_device;
>  	enum phy_mode cur_mode, new_mode;
>  
> +	guard(spinlock_irqsave)(&ch->lock);
> +
>  	if (!ch->is_otg_channel || !rcar_gen3_is_any_otg_rphy_initialized(ch))
>  		return -EIO;
>  
> @@ -415,7 +418,7 @@ static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
>  		val = readl(usb2_base + USB2_ADPCTRL);
>  		writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);
>  	}
> -	msleep(20);
> +	mdelay(20);
>  
>  	writel(0xffffffff, usb2_base + USB2_OBINTSTA);
>  	writel(ch->obint_enable_bits, usb2_base + USB2_OBINTEN);

The fix for the rcar_gen3_init_otg function has not been backported to
the 5.10-stable branch, which leads to a "scheduling while atomic" bug
in that branch:

rcar_gen3_phy_usb2_init()                    ← phy_init() callback
  → guard(spinlock_irqsave)(&ch->lock)       ← acquires spinlock, disabling preemption + IRQs
  → rcar_gen3_init_otg(ch)
      → msleep(20)                           ← BUG: scheduling while atomic!

The patch for 5.10 is available at the following link:
https://web.git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-5.10.y&id=0f86a559900fbe96af08a3a226a86fac27b02b8f

Perhaps the stable patch for the 5.10 branch needs to be updated to
fix this serious bug?

> @@ -456,6 +461,8 @@ static int rcar_gen3_phy_usb2_init(struct phy *p)
>  	void __iomem *usb2_base = channel->base;
>  	u32 val;
>  
> +	guard(spinlock_irqsave)(&channel->lock);
> +
>  	/* Initialize USB2 part */
>  	val = readl(usb2_base + USB2_INT_ENABLE);
>  	val |= USB2_INT_ENABLE_UCOM_INTEN | rphy->int_enable_bits;
> @@ -479,6 +486,8 @@ static int rcar_gen3_phy_usb2_exit(struct phy *p)
>  	void __iomem *usb2_base = channel->base;
>  	u32 val;
>  
> +	guard(spinlock_irqsave)(&channel->lock);
> +
>  	rphy->initialized = false;
>  
>  	val = readl(usb2_base + USB2_INT_ENABLE);



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Re: [PATCH RESEND v3 3/5] phy: renesas: rcar-gen3-usb2: Lock around hardware registers and driver data

[Claudiu Beznea]

On 6/3/26 16:22, Xia Fukun wrote:
> On 5/7/2025 8:50 PM, Claudiu wrote:
> 
>> @@ -348,6 +349,8 @@ static ssize_t role_store(struct device *dev, struct device_attribute *attr,
>>   	bool is_b_device;
>>   	enum phy_mode cur_mode, new_mode;
>>   
>> +	guard(spinlock_irqsave)(&ch->lock);
>> +
>>   	if (!ch->is_otg_channel || !rcar_gen3_is_any_otg_rphy_initialized(ch))
>>   		return -EIO;
>>   
>> @@ -415,7 +418,7 @@ static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
>>   		val = readl(usb2_base + USB2_ADPCTRL);
>>   		writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);
>>   	}
>> -	msleep(20);
>> +	mdelay(20);
>>   
>>   	writel(0xffffffff, usb2_base + USB2_OBINTSTA);
>>   	writel(ch->obint_enable_bits, usb2_base + USB2_OBINTEN);
> The fix for the rcar_gen3_init_otg function has not been backported to
> the 5.10-stable branch, which leads to a "scheduling while atomic" bug
> in that branch:
> 
> rcar_gen3_phy_usb2_init()                    ← phy_init() callback
>    → guard(spinlock_irqsave)(&ch->lock)       ← acquires spinlock, disabling preemption + IRQs
>    → rcar_gen3_init_otg(ch)
>        → msleep(20)                           ← BUG: scheduling while atomic!
> 
> The patch for 5.10 is available at the following link:
> https://web.git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/? 
> h=linux-5.10.y&id=0f86a559900fbe96af08a3a226a86fac27b02b8f
> 
> Perhaps the stable patch for the 5.10 branch needs to be updated to
> fix this serious bug?

Sasha applied today the patch at [1] to solve this problem on v5.10.

Thank you,
Claudiu

[1] 
https://lore.kernel.org/all/20260501225859.504868-1-nobuhiro.iwamatsu.x90@mail.toshiba/

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[PATCH RESEND v3 4/5] phy: renesas: rcar-gen3-usb2: Assert PLL reset on PHY power off

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

Assert PLL reset on PHY power off. This saves power.

Fixes: f3b5a8d9b50d ("phy: rcar-gen3-usb2: Add R-Car Gen3 USB2 PHY driver")
Cc: stable@vger.kernel.org
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v3:
- collected tags

Changes in v2:
- collected tags
- add an empty line after definition of val to get rid of
  the checkpatch.pl warning

 drivers/phy/renesas/phy-rcar-gen3-usb2.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
index 00ce564463de..118899efda70 100644
--- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
+++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
@@ -537,9 +537,17 @@ static int rcar_gen3_phy_usb2_power_off(struct phy *p)
 	struct rcar_gen3_chan *channel = rphy->ch;
 	int ret = 0;
 
-	scoped_guard(spinlock_irqsave, &channel->lock)
+	scoped_guard(spinlock_irqsave, &channel->lock) {
 		rphy->powered = false;
 
+		if (rcar_gen3_are_all_rphys_power_off(channel)) {
+			u32 val = readl(channel->base + USB2_USBCTR);
+
+			val |= USB2_USBCTR_PLL_RST;
+			writel(val, channel->base + USB2_USBCTR);
+		}
+	}
+
 	if (channel->vbus)
 		ret = regulator_disable(channel->vbus);
 
-- 
2.43.0


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[PATCH RESEND v3 5/5] phy: renesas: rcar-gen3-usb2: Set timing registers only once

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

phy-rcar-gen3-usb2 driver exports 4 PHYs. The timing registers are common
to all PHYs. There is no need to set them every time a PHY is initialized.
Set timing register only when the 1st PHY is initialized.

Fixes: f3b5a8d9b50d ("phy: rcar-gen3-usb2: Add R-Car Gen3 USB2 PHY driver")
Cc: stable@vger.kernel.org
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v3:
- collected tags

Changes in v2:
- collected tags

 drivers/phy/renesas/phy-rcar-gen3-usb2.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
index 118899efda70..9fdf17e0848a 100644
--- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
+++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
@@ -467,8 +467,11 @@ static int rcar_gen3_phy_usb2_init(struct phy *p)
 	val = readl(usb2_base + USB2_INT_ENABLE);
 	val |= USB2_INT_ENABLE_UCOM_INTEN | rphy->int_enable_bits;
 	writel(val, usb2_base + USB2_INT_ENABLE);
-	writel(USB2_SPD_RSM_TIMSET_INIT, usb2_base + USB2_SPD_RSM_TIMSET);
-	writel(USB2_OC_TIMSET_INIT, usb2_base + USB2_OC_TIMSET);
+
+	if (!rcar_gen3_is_any_rphy_initialized(channel)) {
+		writel(USB2_SPD_RSM_TIMSET_INIT, usb2_base + USB2_SPD_RSM_TIMSET);
+		writel(USB2_OC_TIMSET_INIT, usb2_base + USB2_OC_TIMSET);
+	}
 
 	/* Initialize otg part (only if we initialize a PHY with IRQs). */
 	if (rphy->int_enable_bits)
-- 
2.43.0


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Re: [PATCH RESEND v3 0/5] phy: renesas: rcar-gen3-usb2: Fixes for Renesas RZ/G3S

[Vinod Koul]

On Wed, 07 May 2025 15:50:27 +0300, Claudiu wrote:
> Series add fixes for the Renesas USB2 PHY driver identified while
> working on the Renesas RZ/G3S USB support. These changes are
> needed for the upcomming RZ/G3S USB support (especially for the
> power management support).
> 
> Series (with [1] on top) was tested on Renesas RZ/G3S with consecutive
> unbind/bind and data transfer tests before/after the unbind/bind.
> 
> [...]

Applied, thanks!

[1/5] phy: renesas: rcar-gen3-usb2: Fix role detection on unbind/bind
      commit: 54c4c58713aaff76c2422ff5750e557ab3b100d7
[2/5] phy: renesas: rcar-gen3-usb2: Move IRQ request in probe
      commit: de76809f60cc938d3580bbbd5b04b7d12af6ce3a
[3/5] phy: renesas: rcar-gen3-usb2: Lock around hardware registers and driver data
      commit: 55a387ebb9219cbe4edfa8ba9996ccb0e7ad4932
[4/5] phy: renesas: rcar-gen3-usb2: Assert PLL reset on PHY power off
      commit: 9ce71e85b29eb63e48e294479742e670513f03a0
[5/5] phy: renesas: rcar-gen3-usb2: Set timing registers only once
      commit: 86e70849f4b2b4597ac9f7c7931f2a363774be25

Best regards,
-- 
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