Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.3 138/200] usb: cdc-acm: handle unlinked urb in acm read callback | Date | Sun, 14 Feb 2016 14:22:25 -0800 |
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4.3-stable review patch. If anyone has any objections, please let me know.
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From: Lu Baolu <baolu.lu@linux.intel.com>
commit 19454462acb1bdef80542061bdc9b410e4ed1ff6 upstream.
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> Acked-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/usb/class/cdc-acm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -428,7 +428,8 @@ static void acm_read_bulk_callback(struc set_bit(rb->index, &acm->read_urbs_free); dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n", __func__, status); - return; + if ((status != -ENOENT) || (urb->actual_length == 0)) + return; } usb_mark_last_busy(acm->dev);
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