linux-kernel - Re: [PATCH] HID: lenovo: Fix middle-button behaviour for system suspend

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Date:   Sun, 24 Sep 2023 09:11:16 +0100
From:   Jamie Lentin <jm@...tin.co.uk>
To:     Martin Kepplinger <martink@...teo.de>
Cc:     jikos@...nel.org, benjamin.tissoires@...hat.com,
        linux-kernel@...r.kernel.org, linux-input@...r.kernel.org
Subject: Re: [PATCH] HID: lenovo: Fix middle-button behaviour for system
 suspend

On 2023-09-21 10:21, Martin Kepplinger wrote:
> After system suspend the middle-button mode is being reset to
> compatibility mode which simply breaks functionality for the devices
> where native mode is configured during probe().
> 
> Fix this by setting native mode in reset_resume() for the appropriate
> devices.
> 
> Fixes: 94eefa271323 ("HID: lenovo: Use native middle-button mode for
> compact keyboards")
> Signed-off-by: Martin Kepplinger <martink@...teo.de>
> ---
>  drivers/hid/hid-lenovo.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
> index 44763c0da444..d20562b9eca6 100644
> --- a/drivers/hid/hid-lenovo.c
> +++ b/drivers/hid/hid-lenovo.c
> @@ -1344,6 +1344,28 @@ static int lenovo_input_configured(struct
> hid_device *hdev,
>  	return 0;
>  }
> 
> +static int __maybe_unused lenovo_resume(struct hid_device *hdev)
> +{
> +	int ret;
> +
> +	switch (hdev->product) {
> +	case USB_DEVICE_ID_LENOVO_CUSBKBD:
> +	case USB_DEVICE_ID_LENOVO_CBTKBD:
> +	case USB_DEVICE_ID_LENOVO_TPIIUSBKBD:
> +	case USB_DEVICE_ID_LENOVO_TPIIBTKBD:
> +		/* Switch middle button to native mode again */
> +		ret = lenovo_send_cmd_cptkbd(hdev, 0x09, 0x01);

This will only reset the middle button state and not the Function key 
state, which I believe has similar problems. This was my attempt at 
solving this:

   
https://github.com/lentinj/linux/commit/f1c4e2de780abf8526bcdc9496c463f1ff4fe53b

...which should ensure everything is in a consistent state with what the 
kernel expects.

I never submitted this since sending commands was sporadically resulting 
in timeouts, although I'm fairly sure it was unrelated to this patch, 
and quite possibly a hardware problem with my keyboard. I'd be 
interested to know how you get on.

Also, the above will send the command to both the USB keyboard & mouse 
devices, only the mouse will respond. So worth prepending something 
like:

	if (((hdev->product == USB_DEVICE_ID_LENOVO_CUSBKBD) ||
	    (hdev->product == USB_DEVICE_ID_LENOVO_TPIIUSBKBD)) &&
	    hdev->type != HID_TYPE_USBMOUSE) {
		hid_dbg(hdev, "Ignoring keyboard half of device\n");
		return 0;
	}

...to avoid sending known-useless messages.

> +		if (ret)
> +			hid_warn(hdev, "Failed to switch middle button: %d\n",
> +				 ret);
> +		break;
> +	default:
> +		ret = 0;
> +		break;
> +	}
> +
> +	return ret;
> +}
> 
>  static const struct hid_device_id lenovo_devices[] = {
>  	{ HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_TPKBD) },
> @@ -1380,6 +1402,9 @@ static struct hid_driver lenovo_driver = {
>  	.raw_event = lenovo_raw_event,
>  	.event = lenovo_event,
>  	.report_fixup = lenovo_report_fixup,
> +#ifdef CONFIG_PM
> +	.reset_resume = lenovo_resume,
> +#endif
>  };
>  module_hid_driver(lenovo_driver);