Date:   Wed, 22 Feb 2023 07:04:12 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Michael Wu <michael@allwinnertech.com>
Cc:     jikos@kernel.org, benjamin.tissoires@redhat.com,
        linux-usb@vger.kernel.org, linux-input@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] HID: usbhid: enable remote wakeup for mice
Message-ID: <Y/WwXBF37hoZBbQa@kroah.com>
References: <20230222013944.31095-1-michael@allwinnertech.com>
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In-Reply-To: <20230222013944.31095-1-michael@allwinnertech.com>
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On Wed, Feb 22, 2023 at 09:39:44AM +0800, Michael Wu wrote:
> This patch fixes a problem that USB mouse can't wake up the device that
> enters standby.

This not a problem, it is that way by design.

> At present, the kernel only checks whether certain USB manufacturers
> support wake-up, which will easily cause inconvenience to the
> development work of other manufacturers and add unnecessary work to the
> maintenance of kernel.
> 
> The USB protocol supports judging whether a usb supports the wake-up
> function, so it should be more reasonable to add a wake-up source by
> directly checking the settings from the USB protocol.

But you do not do that in this patch, why not?

> There was a similar issue on the keyboard before, which was fixed by
> this patch (3d61510f4eca), but now the problem happened on the mouse.
> This patch uses a similar idea to fix this problem.
> 
> Signed-off-by: Michael Wu <michael@allwinnertech.com>
> ---
>  drivers/hid/usbhid/hid-core.c | 8 ++++++++
>  drivers/hid/usbhid/usbmouse.c | 1 +
>  2 files changed, 9 insertions(+)
> 
> diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
> index be4c731aaa65..d3a6755cca09 100644
> --- a/drivers/hid/usbhid/hid-core.c
> +++ b/drivers/hid/usbhid/hid-core.c
> @@ -1189,6 +1189,14 @@ static int usbhid_start(struct hid_device *hid)
>  		device_set_wakeup_enable(&dev->dev, 1);
>  	}
>  
> +	/**
> +	 * NOTE: enable remote wakeup by default for all mouse devices
> +	 * supporting the boot protocol.
> +	 */
> +	if (interface->desc.bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT &&
> +	    interface->desc.bInterfaceProtocol == USB_INTERFACE_PROTOCOL_MOUSE)
> +		device_set_wakeup_enable(&dev->dev, 1);

Sorry, but we can not take this unless it is proven that this will work
properly for all of these devices.  Other operating systems do not do
this last I checked, so there will be problems.

thanks,

greg k-h