From 00529740d1dd0b56f08960968bfdd720f4acc8fb Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Wed, 30 Dec 2015 12:59:08 +0800 Subject: [PATCH] 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 Signed-off-by: Lu Baolu Cc: stable@vger.kernel.org Acked-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- 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 0ecf393a7973..57be981319d7 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -430,7 +430,8 @@ static void acm_read_bulk_callback(struct urb *urb) if (urb->status) { dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n", __func__, urb->status); - return; + if ((urb->status != -ENOENT) || (urb->actual_length == 0)) + return; } usb_mark_last_busy(acm->dev);