usb: Make DELAY_INIT quirk wait 100ms between Get Configuration requests
authorJulius Werner <jwerner@chromium.org>
Tue, 4 Mar 2014 19:27:38 +0000 (11:27 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 7 Mar 2014 19:46:51 +0000 (11:46 -0800)
commitd86db25e53fa69e3e97f3b55dd82a70689787c5d
tree4cd6a19f0f6004f5cce7ddb5a85f52e3db7dd9d0
parente0429362ab15c46ea4d64c3f8c9e0933e48a143a
usb: Make DELAY_INIT quirk wait 100ms between Get Configuration requests

The DELAY_INIT quirk only reduces the frequency of enumeration failures
with the Logitech HD Pro C920 and C930e webcams, but does not quite
eliminate them. We have found that adding a delay of 100ms between the
first and second Get Configuration request makes the device enumerate
perfectly reliable even after several weeks of extensive testing. The
reasons for that are anyone's guess, but since the DELAY_INIT quirk
already delays enumeration by a whole second, wating for another 10th of
that isn't really a big deal for the one other device that uses it, and
it will resolve the problems with these webcams.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/config.c