isp1760_stop() is never called in atomic context. The call chain ending up at isp1760_stop() is: [1] isp1760_stop() <- isp1760_shutdown() isp1760_shutdown() is set as ".shutdown" in struct hc_driver. isp1760_stop() is also set as ".stop" in hc_driver. These functions are not called in atomic context. Despite never getting called from atomic context, isp1760_stop() calls mdelay() to busily wait. This is not necessary and can be replaced with msleep() to avoid busy waiting. This is found by a static analysis tool named DCNS written by myself. And I also manually check it Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> --- drivers/usb/isp1760/isp1760-hcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/isp1760/isp1760-hcd.c b/drivers/usb/isp1760/isp1760-hcd.c index 8e59e0c..5599310 100644 --- a/drivers/usb/isp1760/isp1760-hcd.c +++ b/drivers/usb/isp1760/isp1760-hcd.c @@ -2090,7 +2090,7 @@ static void isp1760_stop(struct usb_hcd *hcd) isp1760_hub_control(hcd, ClearPortFeature, USB_PORT_FEAT_POWER, 1, NULL, 0); - mdelay(20); + msleep(20); spin_lock_irq(&priv->lock); ehci_reset(hcd); -- 1.9.1 -- 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