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authorLu Baolu <baolu.lu@linux.intel.com>2015-12-30 12:59:08 +0800
committerSasha Levin <sasha.levin@oracle.com>2016-02-15 15:45:20 -0500
commit6cdc037a9b649209051e3c982d5fcaf31274cb55 (patch)
treebe92db2c1345730da3cb9b155f49704a6bbde453
parentf75f1b25fb42f28b59d6e050cbdd4440797ac9ad (diff)
usb: cdc-acm: handle unlinked urb in acm read callback
[ Upstream commit 19454462acb1bdef80542061bdc9b410e4ed1ff6 ] 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> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-rw-r--r--drivers/usb/class/cdc-acm.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 0fe15aec7ed0..2bf51b27959b 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -432,7 +432,8 @@ 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);