4.2.8-ckt4 -stable review patch. If anyone has any objections, please let me
know.
---8<------------------------------------------------------------
From: Lu Baolu <baolu...@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.t...@intel.com>
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
Acked-by: Oliver Neukum <oneu...@suse.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <ka...@canonical.com>
---
drivers/usb/class/cdc-acm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 26ca4f9..8cd193b 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -428,7 +428,8 @@ 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);
- return;
+ if ((status != -ENOENT) || (urb->actual_length == 0))
+ return;
}
usb_mark_last_busy(acm->dev);
--
1.9.1
