This is a note to let you know that I've just added the patch titled serial: 8250: omap: Flush PM QOS work on remove to the 4.9-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: serial-8250-omap-flush-pm-qos-work-on-remove.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2fd7b42e09987951017bb54e932143eb9b6430b4 Author: Tony Lindgren <tony@xxxxxxxxxxx> Date: Fri Oct 28 14:00:44 2022 +0300 serial: 8250: omap: Flush PM QOS work on remove [ Upstream commit d0b68629bd2fb61e0171a62f2e8da3db322f5cf6 ] Rebinding 8250_omap in a loop will at some point produce a warning for kernel/power/qos.c:296 cpu_latency_qos_update_request() with error "cpu_latency_qos_update_request called for unknown object". Let's flush the possibly pending PM QOS work scheduled from omap8250_runtime_suspend() before we disable runtime PM. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20221028110044.54719-1-tony@xxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index cecc266b3640..d5962162c590 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -1234,6 +1234,7 @@ static int omap8250_remove(struct platform_device *pdev) pm_runtime_dont_use_autosuspend(&pdev->dev); pm_runtime_put_sync(&pdev->dev); + flush_work(&priv->qos_work); pm_runtime_disable(&pdev->dev); serial8250_unregister_port(priv->line); pm_qos_remove_request(&priv->pm_qos_request);