Commit 55f1a5f7 authored by BH Hsieh's avatar BH Hsieh Committed by Vinod Koul
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phy: tegra: xusb: reset VBUS & ID OVERRIDE 



Observed VBUS_OVERRIDE & ID_OVERRIDE might be programmed
with unexpected value prior to XUSB PADCTL driver, this
could also occur in virtualization scenario.

For example, UEFI firmware programs ID_OVERRIDE=GROUNDED to set
a type-c port to host mode and keeps the value to kernel.
If the type-c port is connected a usb host, below errors can be
observed right after usb host mode driver gets probed. The errors
would keep until usb role class driver detects the type-c port
as device mode and notifies usb device mode driver to set both
ID_OVERRIDE and VBUS_OVERRIDE to correct value by XUSB PADCTL
driver.

[  173.765814] usb usb3-port2: Cannot enable. Maybe the USB cable is bad?
[  173.765837] usb usb3-port2: config error

Taking virtualization into account, asserting XUSB PADCTL
reset would break XUSB functions used by other guest OS,
hence only reset VBUS & ID OVERRIDE of the port in
utmi_phy_init.

Fixes: bbf71168 ("phy: tegra: xusb: Add Tegra186 support")
Cc: stable@vger.kernel.org
Change-Id: Ic63058d4d49b4a1f8f9ab313196e20ad131cc591
Signed-off-by: default avatarBH Hsieh <bhsieh@nvidia.com>
Signed-off-by: default avatarHenry Lin <henryl@nvidia.com>
Link: https://lore.kernel.org/r/20250122105943.8057-1-henryl@nvidia.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 5ab90f40

drivers/phy/tegra/xusb-tegra186.c

+11 −0
Original line number Diff line number Diff line
@@ -928,6 +928,7 @@ static int tegra186_utmi_phy_init(struct phy *phy) 
	unsigned int index = lane->index;

	struct device *dev = padctl->dev;

	int err;

	u32 reg;



	port = tegra_xusb_find_usb2_port(padctl, index);

	if (!port) {
@@ -935,6 +936,16 @@ static int tegra186_utmi_phy_init(struct phy *phy) 
		return -ENODEV;

	}



	if (port->mode == USB_DR_MODE_OTG ||

	    port->mode == USB_DR_MODE_PERIPHERAL) {

		/* reset VBUS&ID OVERRIDE */

		reg = padctl_readl(padctl, USB2_VBUS_ID);

		reg &= ~VBUS_OVERRIDE;

		reg &= ~ID_OVERRIDE(~0);

		reg |= ID_OVERRIDE_FLOATING;

		padctl_writel(padctl, reg, USB2_VBUS_ID);

	}



	if (port->supply && port->mode == USB_DR_MODE_HOST) {

		err = regulator_enable(port->supply);

		if (err) {