When transitioning from USB_ROLE_DEVICE to USB_ROLE_NONE, the code assumed that the regulator should be disabled. However, if the regulator is marked as always-on, regulator_is_enabled() continues to return true, leading to an incorrect attempt to disable a regulator which is not enabled.
This can result in warnings such as:
[ 250.155624] WARNING: CPU: 1 PID: 7326 at drivers/regulator/core.c:3004 _regulator_disable+0xe4/0x1a0 [ 250.155652] unbalanced disables for VIN_SYS_5V0
To fix this, we move the regulator control logic into tegra186_xusb_padctl_id_override() function since it's directly related to the ID override state. The regulator is now only disabled when the role transitions from USB_ROLE_HOST to USB_ROLE_NONE, by checking the VBUS_ID register. This ensures that regulator enable/disable operations are properly balanced and only occur when actually transitioning to/from host mode.
Fixes: 49d46e3c7e59 ("phy: tegra: xusb: Add set_mode support for UTMI phy on Tegra186") Cc: stable@vger.kernel.org Signed-off-by: Wayne Chang waynec@nvidia.com --- drivers/phy/tegra/xusb-tegra186.c | 59 +++++++++++++++++++------------ 1 file changed, 37 insertions(+), 22 deletions(-)
diff --git a/drivers/phy/tegra/xusb-tegra186.c b/drivers/phy/tegra/xusb-tegra186.c index fae6242aa730..1b35d50821f7 100644 --- a/drivers/phy/tegra/xusb-tegra186.c +++ b/drivers/phy/tegra/xusb-tegra186.c @@ -774,13 +774,15 @@ static int tegra186_xusb_padctl_vbus_override(struct tegra_xusb_padctl *padctl, }
static int tegra186_xusb_padctl_id_override(struct tegra_xusb_padctl *padctl, - bool status) + struct tegra_xusb_usb2_port *port, bool status) { - u32 value; + u32 value, id_override; + int err = 0;
dev_dbg(padctl->dev, "%s id override\n", status ? "set" : "clear");
value = padctl_readl(padctl, USB2_VBUS_ID); + id_override = value & ID_OVERRIDE(~0);
if (status) { if (value & VBUS_OVERRIDE) { @@ -791,15 +793,35 @@ static int tegra186_xusb_padctl_id_override(struct tegra_xusb_padctl *padctl, value = padctl_readl(padctl, USB2_VBUS_ID); }
- value &= ~ID_OVERRIDE(~0); - value |= ID_OVERRIDE_GROUNDED; + if (id_override != ID_OVERRIDE_GROUNDED) { + value &= ~ID_OVERRIDE(~0); + value |= ID_OVERRIDE_GROUNDED; + padctl_writel(padctl, value, USB2_VBUS_ID); + + err = regulator_enable(port->supply); + if (err) { + dev_err(padctl->dev, "Failed to enable regulator: %d\n", err); + return err; + } + } } else { - value &= ~ID_OVERRIDE(~0); - value |= ID_OVERRIDE_FLOATING; + if (id_override == ID_OVERRIDE_GROUNDED) { + /* + * The regulator is disabled only when the role transitions + * from USB_ROLE_HOST to USB_ROLE_NONE. + */ + err = regulator_disable(port->supply); + if (err) { + dev_err(padctl->dev, "Failed to disable regulator: %d\n", err); + return err; + } + + value &= ~ID_OVERRIDE(~0); + value |= ID_OVERRIDE_FLOATING; + padctl_writel(padctl, value, USB2_VBUS_ID); + } }
- padctl_writel(padctl, value, USB2_VBUS_ID); - return 0; }
@@ -818,27 +840,20 @@ static int tegra186_utmi_phy_set_mode(struct phy *phy, enum phy_mode mode,
if (mode == PHY_MODE_USB_OTG) { if (submode == USB_ROLE_HOST) { - tegra186_xusb_padctl_id_override(padctl, true); - - err = regulator_enable(port->supply); + err = tegra186_xusb_padctl_id_override(padctl, port, true); + if (err) + goto out; } else if (submode == USB_ROLE_DEVICE) { tegra186_xusb_padctl_vbus_override(padctl, true); } else if (submode == USB_ROLE_NONE) { - /* - * When port is peripheral only or role transitions to - * USB_ROLE_NONE from USB_ROLE_DEVICE, regulator is not - * enabled. - */ - if (regulator_is_enabled(port->supply)) - regulator_disable(port->supply); - - tegra186_xusb_padctl_id_override(padctl, false); + err = tegra186_xusb_padctl_id_override(padctl, port, false); + if (err) + goto out; tegra186_xusb_padctl_vbus_override(padctl, false); } } - +out: mutex_unlock(&padctl->lock); - return err; }
On 02/05/2025 10:26, Wayne Chang wrote:
When transitioning from USB_ROLE_DEVICE to USB_ROLE_NONE, the code assumed that the regulator should be disabled. However, if the regulator is marked as always-on, regulator_is_enabled() continues to return true, leading to an incorrect attempt to disable a regulator which is not enabled.
This can result in warnings such as:
[ 250.155624] WARNING: CPU: 1 PID: 7326 at drivers/regulator/core.c:3004 _regulator_disable+0xe4/0x1a0 [ 250.155652] unbalanced disables for VIN_SYS_5V0
To fix this, we move the regulator control logic into tegra186_xusb_padctl_id_override() function since it's directly related to the ID override state. The regulator is now only disabled when the role transitions from USB_ROLE_HOST to USB_ROLE_NONE, by checking the VBUS_ID register. This ensures that regulator enable/disable operations are properly balanced and only occur when actually transitioning to/from host mode.
Fixes: 49d46e3c7e59 ("phy: tegra: xusb: Add set_mode support for UTMI phy on Tegra186") Cc: stable@vger.kernel.org Signed-off-by: Wayne Chang waynec@nvidia.com
drivers/phy/tegra/xusb-tegra186.c | 59 +++++++++++++++++++------------ 1 file changed, 37 insertions(+), 22 deletions(-)
diff --git a/drivers/phy/tegra/xusb-tegra186.c b/drivers/phy/tegra/xusb-tegra186.c index fae6242aa730..1b35d50821f7 100644 --- a/drivers/phy/tegra/xusb-tegra186.c +++ b/drivers/phy/tegra/xusb-tegra186.c @@ -774,13 +774,15 @@ static int tegra186_xusb_padctl_vbus_override(struct tegra_xusb_padctl *padctl, } static int tegra186_xusb_padctl_id_override(struct tegra_xusb_padctl *padctl,
bool status)
struct tegra_xusb_usb2_port *port, bool status)
- u32 value;
- u32 value, id_override;
- int err = 0;
dev_dbg(padctl->dev, "%s id override\n", status ? "set" : "clear"); value = padctl_readl(padctl, USB2_VBUS_ID);
- id_override = value & ID_OVERRIDE(~0);
if (status) { if (value & VBUS_OVERRIDE) { @@ -791,15 +793,35 @@ static int tegra186_xusb_padctl_id_override(struct tegra_xusb_padctl *padctl, value = padctl_readl(padctl, USB2_VBUS_ID); }
value &= ~ID_OVERRIDE(~0);value |= ID_OVERRIDE_GROUNDED;
if (id_override != ID_OVERRIDE_GROUNDED) {value &= ~ID_OVERRIDE(~0);value |= ID_OVERRIDE_GROUNDED;padctl_writel(padctl, value, USB2_VBUS_ID);err = regulator_enable(port->supply);if (err) {dev_err(padctl->dev, "Failed to enable regulator: %d\n", err);return err;}}
value &= ~ID_OVERRIDE(~0);value |= ID_OVERRIDE_FLOATING;
if (id_override == ID_OVERRIDE_GROUNDED) {/** The regulator is disabled only when the role transitions* from USB_ROLE_HOST to USB_ROLE_NONE.*/err = regulator_disable(port->supply);if (err) {dev_err(padctl->dev, "Failed to disable regulator: %d\n", err);return err;}value &= ~ID_OVERRIDE(~0);value |= ID_OVERRIDE_FLOATING;padctl_writel(padctl, value, USB2_VBUS_ID);}
- padctl_writel(padctl, value, USB2_VBUS_ID);
- return 0; }
@@ -818,27 +840,20 @@ static int tegra186_utmi_phy_set_mode(struct phy *phy, enum phy_mode mode, if (mode == PHY_MODE_USB_OTG) { if (submode == USB_ROLE_HOST) {
tegra186_xusb_padctl_id_override(padctl, true);err = regulator_enable(port->supply);
err = tegra186_xusb_padctl_id_override(padctl, port, true);if (err)goto out;
/** When port is peripheral only or role transitions to* USB_ROLE_NONE from USB_ROLE_DEVICE, regulator is not* enabled.*/if (regulator_is_enabled(port->supply))regulator_disable(port->supply);tegra186_xusb_padctl_id_override(padctl, false);
err = tegra186_xusb_padctl_id_override(padctl, port, false);if (err)goto out; tegra186_xusb_padctl_vbus_override(padctl, false);
+out: mutex_unlock(&padctl->lock);
- return err; }
Reviewed-by: Jon Hunter jonathanh@nvidia.com Tested-by: Jon Hunter jonathanh@nvidia.com
Thanks for fixing this!
Jon
linux-stable-mirror@lists.linaro.org
-
Jon Hunter -
Wayne Chang