[U-Boot] [PATCH 1/4] usb: xhci: Set accurate add context flags when updating hub attributes

[Bin Meng]

If a USB 3.0 hub is plugged into the root port of the xHC, the xHCI
driver will issue a 'Configure Endpoint' command to the xHC for it
to update its internal data structure for this hub device. The hub
attributes are in the slot context so we need tell xHC to update the
slot context by setting the add context flags of the input control
context to only cover the slot context.

At present the add context flags is or'ed with the slot context bit,
but it should really be accurately set to the slot context, as the
variable that holds the value of the add context flags comes from
whatever was set in the last command execution, which may contain
additional contexts that 'Configure Endpoint' command should not
touch. Some xHC implementations like x86 don't complain such, but
it was observed on Renesas RCar Gen3 platform that the RCar xHC
complains with a 'TRB error' completion codes as the response.

Reported-by: Marek Vasut <marek.vasut at gmail.com>
Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
Tested-by: Marek Vasut <marek.vasut at gmail.com>
Tested-by: Matthias Blankertz <matthias.blankertz at cetitec.com>
---

 drivers/usb/host/xhci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 3adb002..565948c 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1424,7 +1424,7 @@ static int xhci_update_hub_device(struct udevice *dev, struct usb_device *udev)
 
 	ctrl_ctx = xhci_get_input_control_ctx(in_ctx);
 	/* Initialize the input context control */
-	ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
+	ctrl_ctx->add_flags = cpu_to_le32(SLOT_FLAG);
 	ctrl_ctx->drop_flags = 0;
 
 	xhci_inval_cache((uintptr_t)out_ctx->bytes, out_ctx->size);
-- 
2.7.4