This is a note to let you know that I've just added the patch titled
xhci: Fix enumeration issue when setting max packet size for FS devices.
to the 5.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xhci-fix-enumeration-issue-when-setting-max-packet-size-for-fs-devices.patch
and it can be found in the queue-5.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a73d9d9cfc3cfceabd91fb0b0c13e4062b6dbcd7 Mon Sep 17 00:00:00 2001
From: Al Cooper <alcooperx@xxxxxxxxx>
Date: Wed, 24 Jun 2020 16:59:46 +0300
Subject: xhci: Fix enumeration issue when setting max packet size for FS devices.
From: Al Cooper <alcooperx@xxxxxxxxx>
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@xxxxxxxxxxxxxxx
Signed-off-by: Al Cooper <alcooperx@xxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200624135949.22611-3-mathias.nyman@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1430,6 +1430,7 @@ static int xhci_check_maxpacket(struct x
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));
Patches currently in stable-queue which might be from alcooperx@xxxxxxxxx are
queue-5.7/xhci-fix-enumeration-issue-when-setting-max-packet-size-for-fs-devices.patch
