UPSTREAM: cdc-wdm: Clear read pipeline in case of error
Implemented queued response handling. This queue is processed every time the
WDM_READ flag is cleared.
In case of a read error, userspace may not actually read the data, since the
driver returns an error through wdm_poll. After this, the underlying device may
attempt to send us more data, but the queue is not processed. While userspace is
also blocked, because the read error is never cleared.
After this patch, we proactively process the queue on a read error. If there was
an outstanding response to handle, that will clear the error (or go through the
same logic again, if another read error occurs). If there was no outstanding
response, this will bring the queue size back to 0, unblocking a future response
from the underlying device.
Signed-off-by: Robert Foss <robert.foss@collabora.com>
Tested-by: Robert Foss <robert.foss@collabora.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit c1da59dad0ebd3f9bd238f3fff82b1f7ffda7829)
BUG=chromium:682469
TEST=Run network3g tests on Kip and Blaze with MBIM modem.
Change-Id: Id5f32b7e7439579656dd1f69a8ef17126a789ad5
Signed-off-by: Ben Chan <benchan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/430358
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
1 file changed
