xhci: Add quirk to workaround the errata seen on Cavium Thunder-X2 Soc
Implement workaround for ThunderX2 Errata-129 (documented in
CN99XX Known Issues" available at Cavium support site).
As per ThunderX2errata-129, USB 2 device may come up as USB 1
if a connection to a USB 1 device is followed by another connection to
a USB 2 device, the link will come up as USB 1 for the USB 2 device.
Resolution: Reset the PHY after the USB 1 device is disconnected.
The PHY reset sequence is done using private registers in XHCI register
space. After the PHY is reset we check for the PLL lock status and retry
the operation if it fails. From our tests, retrying 4 times is sufficient.
Add a new quirk flag XHCI_RESET_PLL_ON_DISCONNECT to invoke the workaround
in handle_xhci_port_status().
Cc: stable@vger.kernel.org
Signed-off-by: George Cherian <george.cherian@cavium.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 5f0c4f1..260b259 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1849,6 +1849,7 @@ struct xhci_hcd {
#define XHCI_INTEL_USB_ROLE_SW BIT_ULL(31)
#define XHCI_ZERO_64B_REGS BIT_ULL(32)
#define XHCI_DEFAULT_PM_RUNTIME_ALLOW BIT_ULL(33)
+#define XHCI_RESET_PLL_ON_DISCONNECT BIT_ULL(34)
unsigned int num_active_eps;
unsigned int limit_active_eps;