If suspend callback fails in system sleep context, usb core will ignore the failure and let system sleep go ahead further, so this patch comments on the case and requires that both usbnet_suspend() and subdriver->suspend() MUST return 0 in system sleep context. Cc: Bjørn Mork <bjorn@xxxxxxx> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx> --- drivers/net/usb/qmi_wwan.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c index efb5c7c..8a60bdd 100644 --- a/drivers/net/usb/qmi_wwan.c +++ b/drivers/net/usb/qmi_wwan.c @@ -288,6 +288,11 @@ static int qmi_wwan_suspend(struct usb_interface *intf, pm_message_t message) struct qmi_wwan_state *info = (void *)&dev->data; int ret; + /* + * Both usbnet_suspend() and subdriver->suspend() MUST return 0 + * in system sleep context, otherwise, the resume callback has + * to recover device from previous suspend failure. + */ ret = usbnet_suspend(intf, message); if (ret < 0) goto err; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html