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xhci: Fix enumeration issue when setting max packet size for FS devices.

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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 <alcooperx@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200624135949.22611-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Al Cooper 2020-06-24 16:59:46 +03:00 • committed by Sasha Levin
parent d7ed5fc0c1
commit 26a7aefb9a
1 changed files with 1 additions and 0 deletions

1
drivers/usb/host/xhci.c
View file

@ -1405,6 +1405,7 @@ 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));