tree 4c1fd832ca92cb43f724441a03e92ba97b20ed0e
parent 5a77c5050ee4f93e3c0696e6b2d7e8683e63cc95
author Alan Stern <stern@rowland.harvard.edu> 1605805240 -0500
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1606894485 +0100

USB: core: Fix regression in Hercules audio card

commit 184eead057cc7e803558269babc1f2cfb9113ad1 upstream

Commit 3e4f8e21c4f2 ("USB: core: fix check for duplicate endpoints")
aimed to make the USB stack more reliable by detecting and skipping
over endpoints that are duplicated between interfaces.  This caused a
regression for a Hercules audio card (reported as Bugzilla #208357),
which contains such non-compliant duplications.  Although the
duplications are harmless, skipping the valid endpoints prevented the
device from working.

This patch fixes the regression by adding ENDPOINT_IGNORE quirks for
the Hercules card, telling the kernel to ignore the invalid duplicate
endpoints and thereby allowing the valid endpoints to be used as
intended.

Fixes: 3e4f8e21c4f2 ("USB: core: fix check for duplicate endpoints")
CC: <stable@vger.kernel.org>
Reported-by: Alexander Chalikiopoulos <bugzilla.kernel.org@mrtoasted.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20201119170040.GA576844@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[sudip: use usb_endpoint_blacklist and USB_QUIRK_ENDPOINT_BLACKLIST]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>