From: Al Cooper alcooperx@gmail.com
Unable to complete the enumeration of a USB TV Tuner device.
Per XHCI spec (4.6.5), the EP state field of the input context shall be cleared for a set address command. In the special case of an FS device that has "MaxPacketSize0 = 8", the Linux XHCI driver does not do this before evaluating the context. With an XHCI controller that checks the EP state field for parameter context error this causes a problem in cases such as the device getting reset again after enumeration.
When that field is cleared, the problem does not occur.
This was found and fixed by Sasi Kumar.
Cc: stable@vger.kernel.org Signed-off-by: Al Cooper alcooperx@gmail.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com --- drivers/usb/host/xhci.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index bee5deccc83d..03b64b73eb99 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1430,6 +1430,7 @@ static int xhci_check_maxpacket(struct xhci_hcd *xhci, unsigned int slot_id, xhci->devs[slot_id]->out_ctx, ep_index);
ep_ctx = xhci_get_ep_ctx(xhci, command->in_ctx, ep_index); + ep_ctx->ep_info &= cpu_to_le32(~EP_STATE_MASK);/* must clear */ ep_ctx->ep_info2 &= cpu_to_le32(~MAX_PACKET_MASK); ep_ctx->ep_info2 |= cpu_to_le32(MAX_PACKET(max_packet_size));