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phy: tegra: xusb: reset VBUS & ID OVERRIDE
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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: bbf7116 ("phy: tegra: xusb: Add Tegra186 support")
Cc: stable@vger.kernel.org
Change-Id: Ic63058d4d49b4a1f8f9ab313196e20ad131cc591
Signed-off-by: BH Hsieh <bhsieh@nvidia.com>
Signed-off-by: Henry Lin <henryl@nvidia.com>
Link: https://lore.kernel.org/r/20250122105943.8057-1-henryl@nvidia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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BH Hsieh authored and Vinod Koul committed Feb 14, 2025
1 parent 5ab90f4 commit 55f1a5f
Showing 1 changed file with 11 additions and 0 deletions.
11 changes: 11 additions & 0 deletions drivers/phy/tegra/xusb-tegra186.c
Original file line number Diff line number Diff line change
Expand Up @@ -928,13 +928,24 @@ 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) {
dev_err(dev, "no port found for USB2 lane %u\n", index);
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) {
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