FAILED: patch "[PATCH] USB: dwc2: shut down wakeup timer before freeing HCD state" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x fd772af9512cdecb83de34a461801533828e77fd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026100531-stamp-citable-47a4@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From fd772af9512cdecb83de34a461801533828e77fd Mon Sep 17 00:00:00 2001
From: Runyu Xiao <runyu.xiao@seu.edu.cn>
Date: Fri, 4 Sep 2026 14:53:23 +0800
Subject: [PATCH] USB: dwc2: shut down wakeup timer before freeing HCD state

dwc2_wakeup_detected() accesses the DWC2 host state and can rearm the
wakeup timer.  dwc2_hcd_free() currently deletes the timer only after
freeing host-owned state, and timer_delete() does not synchronize a
callback or prevent it from being queued again.

Stop and shut down the timer in dwc2_hcd_release(), before the HCD
resources are freed.  This covers both the HCD initialization error path
and normal HCD removal.

Fixes: 7359d482eb4d ("staging: HCD files for the DWC2 driver")
Cc: stable <stable@kernel.org>
Assisted-by: Codex:GPT-5
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://patch.msgid.link/20260904065323.4047026-1-runyu.xiao@seu.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 2414291aa908..cd0dc876b421 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -5082,14 +5082,13 @@ static void dwc2_hcd_free(struct dwc2_hsotg *hsotg)
 	}
 
 	cancel_work_sync(&hsotg->phy_reset_work);
-
-	timer_delete(&hsotg->wkp_timer);
 }
 
 static void dwc2_hcd_release(struct dwc2_hsotg *hsotg)
 {
 	/* Turn off all host-specific interrupts */
 	dwc2_disable_host_interrupts(hsotg);
+	timer_shutdown_sync(&hsotg->wkp_timer);
 
 	dwc2_hcd_free(hsotg);
 }