Commit 975f94c7 authored May 12, 2021 by Chunfeng Yun Committed by Greg Kroah-Hartman May 13, 2021

usb: core: hub: fix race condition about TRSMRCY of resume



This may happen if the port becomes resume status exactly
when usb_port_resume() gets port status, it still need provide
a TRSMCRY time before access the device.

CC: <stable@vger.kernel.org>
Reported-by: Tianping Fang <tianping.fang@mediatek.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20210512020738.52961-1-chunfeng.yun@mediatek.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 12701ce5

drivers/usb/core/hub.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -3642,9 +3642,6 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
		* sequence.
		*/
		status = hub_port_status(hub, port1, &portstatus, &portchange);

		/* TRSMRCY = 10 msec */
		msleep(10);
		}

		SuspendCleared:
		@@ -3659,6 +3656,9 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
		usb_clear_port_feature(hub->hdev, port1,
		USB_PORT_FEAT_C_SUSPEND);
		}

		/* TRSMRCY = 10 msec */
		msleep(10);
		}

		if (udev->persist_enabled)