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Code

phy: tegra: xusb: Fix unbalanced regulator disable in UTMI PHY mode

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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: 49d46e3c7e ("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>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20250502092606.2275682-1-waynec@nvidia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Wayne Chang 2025-05-02 17:26:06 +08:00 committed by Vinod Koul
parent 7be54870e9
commit cefc1caee9
1 changed files with 38 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
drivers/phy/tegra/xusb-tegra186.c
View File

@ -783,13 +783,15 @@ 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) {
@ -800,14 +802,34 @@ static int tegra186_xusb_padctl_id_override(struct tegra_xusb_padctl *padctl,
value = padctl_readl(padctl, USB2_VBUS_ID);
}
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);
}
}
return 0;
}
@ -827,27 +849,20 @@ 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;
}