Re: [PATCH] USB: core: Enable root_hub's remote wakeup for wakeup sources

[Greg Kroah-Hartman]

On Fri, Jan 31, 2025 at 06:06:30PM +0800, Huacai Chen wrote:
> Now we only enable the remote wakeup function for the USB wakeup source
> itself at usb_port_suspend(). But on pre-XHCI controllers this is not
> enough to enable the S3 wakeup function for USB keyboards, so we also
> enable the root_hub's remote wakeup (and disable it on error). Frankly
> this is unnecessary for XHCI, but enable it unconditionally make code
> simple and seems harmless.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>

What commit id does this fix?

> ---
>  drivers/usb/core/hub.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index c3f839637cb5..efd6374ccd1d 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -3480,6 +3480,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
>  			if (PMSG_IS_AUTO(msg))
>  				goto err_wakeup;
>  		}
> +		usb_enable_remote_wakeup(udev->bus->root_hub);
>  	}
>  
>  	/* disable USB2 hardware LPM */
> @@ -3543,8 +3544,10 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
>  		/* Try to enable USB2 hardware LPM again */
>  		usb_enable_usb2_hardware_lpm(udev);
>  
> -		if (udev->do_remote_wakeup)
> +		if (udev->do_remote_wakeup) {
>  			(void) usb_disable_remote_wakeup(udev);
> +			(void) usb_disable_remote_wakeup(udev->bus->root_hub);

This feels wrong, what about all of the devices inbetween this device
and the root hub?

thanks,

greg k-h