From: BH Hsieh <bhsieh@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Change-Id: Ic63058d4d49b4a1f8f9ab313196e20ad131cc591
Signed-off-by: BH Hsieh <bhsieh@xxxxxxxxxx>
Signed-off-by: Henry Lin <henryl@xxxxxxxxxx>
---
V1 -> V2: Only reset VBUS/ID OVERRIDE for otg/peripheral port
drivers/phy/tegra/xusb-tegra186.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/phy/tegra/xusb-tegra186.c b/drivers/phy/tegra/xusb-tegra186.c
index 0f60d5d1c167..fae6242aa730 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 +936,16 @@ 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) {
--
2.17.1
