[PATCH] usb: core: hub: fix race condition about TRSMRCY of resume

From: Chunfeng Yun
Date: Tue May 11 2021 - 06:21:59 EST


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.

Reported-by: Tianping Fang <tianping.fang@xxxxxxxxxxxx>
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/core/hub.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b2bc4b7c4289..fc7d6cdacf16 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -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)
--
2.18.0