This is a note to let you know that I've just added the patch titled usb: core: hub: fix race condition about TRSMRCY of resume to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-core-hub-fix-race-condition-about-trsmrcy-of-resume.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 975f94c7d6c306b833628baa9aec3f79db1eb3a1 Mon Sep 17 00:00:00 2001 From: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> Date: Wed, 12 May 2021 10:07:38 +0800 Subject: usb: core: hub: fix race condition about TRSMRCY of resume From: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> commit 975f94c7d6c306b833628baa9aec3f79db1eb3a1 upstream. 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@xxxxxxxxxxxxxxx> Reported-by: Tianping Fang <tianping.fang@xxxxxxxxxxxx> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210512020738.52961-1-chunfeng.yun@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/core/hub.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -3574,9 +3574,6 @@ int usb_port_resume(struct usb_device *u * sequence. */ status = hub_port_status(hub, port1, &portstatus, &portchange); - - /* TRSMRCY = 10 msec */ - msleep(10); } SuspendCleared: @@ -3591,6 +3588,9 @@ int usb_port_resume(struct usb_device *u usb_clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_SUSPEND); } + + /* TRSMRCY = 10 msec */ + msleep(10); } if (udev->persist_enabled) Patches currently in stable-queue which might be from chunfeng.yun@xxxxxxxxxxxx are queue-5.4/usb-core-hub-fix-race-condition-about-trsmrcy-of-resume.patch