From a368c2481d9a924170acbc00671bae0fc2dcc4e8 Mon Sep 17 00:00:00 2001 From: Al Cooper Date: Wed, 24 Jun 2020 16:59:46 +0300 Subject: [PATCH] xhci: Fix enumeration issue when setting max packet size for FS devices. commit a73d9d9cfc3cfceabd91fb0b0c13e4062b6dbcd7 upstream. 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 Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20200624135949.22611-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- 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 dca5f14b54d9..e602dd981b86 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1352,6 +1352,7 @@ 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));