Hi, Greg,
On Fri, Jan 31, 2025 at 6:49 PM Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
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@vger.kernel.org Signed-off-by: Huacai Chen chenhuacai@loongson.cn
What commit id does this fix?
It seems this problem exist from the first place (at least >=4.19).
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?
Yes, if there are other hubs between the root hub and keyboard, this patch still cannot fix the wakeup problem. I have tried to enable every hub in the link, but failed. Because I found many hubs lost power during suspend. So this patch can only fixes the most usual cases.
Huacai
thanks,
greg k-h