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@xxxxxxxxx> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Acked-by: Oliver Neukum <oneukum@xxxxxxxx> --- drivers/usb/class/cdc-acm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) change log: v1->v2: add Acked-by: Oliver Neukum <oneukum@xxxxxxxx>. v2->v3: add the change log. 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); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
