From: BH Hsieh bhsieh@nvidia.com
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: bbf711682cd5 ("phy: tegra: xusb: Add Tegra186 support") Cc: stable@vger.kernel.org Signed-off-by: BH Hsieh bhsieh@nvidia.com Signed-off-by: Henry Lin henryl@nvidia.com --- drivers/phy/tegra/xusb-tegra186.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/phy/tegra/xusb-tegra186.c b/drivers/phy/tegra/xusb-tegra186.c index 0f60d5d1c167..34c6d424a3e8 100644 --- a/drivers/phy/tegra/xusb-tegra186.c +++ b/drivers/phy/tegra/xusb-tegra186.c @@ -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 +936,13 @@ static int tegra186_utmi_phy_init(struct phy *phy) return -ENODEV; }
+ /* 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) {