Commit 19454462 authored Dec 30, 2015 by Lu Baolu Committed by Greg Kroah-Hartman Jan 24, 2016

usb: cdc-acm: handle unlinked urb in acm read callback



In current acm driver, the bulk-in callback function ignores the
URBs unlinked in usb core.

This causes unexpected data loss in some cases. For example,
runtime suspend entry will unlinked all urbs and set urb->status
to -ENOENT even those urbs might have data not processed yet.
Hence, data loss occurs.

This patch lets bulk-in callback function handle unlinked urbs
to avoid data loss.

Signed-off-by: Tang Jian Qiang <jianqiang.tang@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Cc: stable@vger.kernel.org
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 92e963f5

drivers/usb/class/cdc-acm.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -428,6 +428,7 @@ static void acm_read_bulk_callback(struct urb *urb)
		set_bit(rb->index, &acm->read_urbs_free);
		dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n",
		__func__, status);
		if ((status != -ENOENT) \|\| (urb->actual_length == 0))
		return;
		}