Re: [PATCH 1/2] HID: quirks: add quirk to always keep device open

[Benjamin Tissoires <bentiss@kernel.org>]

On Mar 03 2026, leo vriska wrote:
> Some devices expect the host to open the device shortly after it is
> connected. If this does not occur, they may freeze or disconnect. A
> quirk allows these devices to function properly without userspace hacks.
> 
> The existing hid-axff driver solves this problem for some generic
> controllers. This implementation is modelled after that driver, which
> still needs to exist for force feedback on the controllers that use it.

It seems 2/2 is dealing with a USB device. So why not simply make use of
HID_QUIRK_ALWAYS_POLL?

Cheers,
Benjamin

> 
> Signed-off-by: leo vriska <leo@60228.dev>
> ---
>  drivers/hid/hid-generic.c | 23 ++++++++++++++++++++++-
>  include/linux/hid.h       |  2 ++
>  2 files changed, 24 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c
> index c2de916747de..0595e653b7e7 100644
> --- a/drivers/hid/hid-generic.c
> +++ b/drivers/hid/hid-generic.c
> @@ -67,7 +67,27 @@ static int hid_generic_probe(struct hid_device *hdev,
>  	if (ret)
>  		return ret;
>  
> -	return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
> +	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
> +	if (ret)
> +		return ret;
> +
> +	if (hdev->quirks & HID_QUIRK_KEEP_OPEN) {
> +		ret = hid_hw_open(hdev);
> +		if (ret) {
> +			hid_hw_stop(hdev);
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static void hid_generic_remove(struct hid_device *hdev)
> +{
> +	if (hdev->quirks & HID_QUIRK_KEEP_OPEN)
> +		hid_hw_close(hdev);
> +
> +	hid_hw_stop(hdev);
>  }
>  
>  static int hid_generic_reset_resume(struct hid_device *hdev)
> @@ -89,6 +109,7 @@ static struct hid_driver hid_generic = {
>  	.id_table = hid_table,
>  	.match = hid_generic_match,
>  	.probe = hid_generic_probe,
> +	.remove = hid_generic_remove,
>  	.reset_resume = hid_generic_reset_resume,
>  };
>  module_hid_driver(hid_generic);
> diff --git a/include/linux/hid.h b/include/linux/hid.h
> index 2990b9f94cb5..9d0ab7c217f3 100644
> --- a/include/linux/hid.h
> +++ b/include/linux/hid.h
> @@ -388,6 +388,7 @@ struct hid_item {
>   * | @HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE:
>   * | @HID_QUIRK_IGNORE_SPECIAL_DRIVER
>   * | @HID_QUIRK_POWER_ON_AFTER_BACKLIGHT
> + * | @HID_QUIRK_KEEP_OPEN:
>   * | @HID_QUIRK_FULLSPEED_INTERVAL:
>   * | @HID_QUIRK_NO_INIT_REPORTS:
>   * | @HID_QUIRK_NO_IGNORE:
> @@ -416,6 +417,7 @@ struct hid_item {
>  #define HID_QUIRK_NOINVERT			BIT(21)
>  #define HID_QUIRK_IGNORE_SPECIAL_DRIVER		BIT(22)
>  #define HID_QUIRK_POWER_ON_AFTER_BACKLIGHT	BIT(23)
> +#define HID_QUIRK_KEEP_OPEN			BIT(24)
>  #define HID_QUIRK_FULLSPEED_INTERVAL		BIT(28)
>  #define HID_QUIRK_NO_INIT_REPORTS		BIT(29)
>  #define HID_QUIRK_NO_IGNORE			BIT(30)
> -- 
> 2.53.0
>