From 291625aa7c42c080fcf67f64f47c42d3598bf80d 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 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 Signed-off-by: Lu Baolu Acked-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman [ luis: backported to 3.16: - use 'urb->status' instead of local variable 'status' - adjusted context ] Signed-off-by: Luis Henriques --- 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 f2dc4628fb053..9cda90098a57d 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -427,7 +427,8 @@ 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); -- 2.47.3