Re: [PATCH 12/26] Input: maplecontrol - remove unused mdev->driver assignment

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Missing `input_sync()` after reporting events in the maple controller callback.
--

commit 0fbd521bb62afe1470ddde2cd989f82804cfb127
Author: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: maplecontrol - remove unused mdev->driver assignment

The driver field in struct maple_device is no longer used since commit
1795cf48b322 ("sh/maple: clean maple bus code") which removed the reading
of this field. Remove the unused assignment to mdev->driver and the now
unused mdrv variable in probe_maple_controller.

> diff --git a/drivers/input/joystick/maplecontrol.c b/drivers/input/joystick/maplecontrol.c
> index 79cec89ad52a9..955e01bcfa0c1 100644
> --- a/drivers/input/joystick/maplecontrol.c
> +++ b/drivers/input/joystick/maplecontrol.c
> @@ -95,7 +95,6 @@ static int probe_maple_controller(struct device *dev)
>  	};
>  
>  	struct maple_device *mdev = to_maple_dev(dev);
> -	struct maple_driver *mdrv = to_maple_driver(dev->driver);
>  	int i, error;
>  	struct dc_pad *pad;
>  	struct input_dev *idev;
> @@ -138,9 +137,6 @@ static int probe_maple_controller(struct device *dev)
>  	error = input_register_device(idev);
>  	if (error)
>  		goto fail;
> -
> -	mdev->driver = mdrv;
> -
>  	return 0;
>  
>  fail:

[Severity: High]
This isn't a bug introduced by this patch, but I noticed an issue in this
file while reviewing the driver.

Does the hardware callback need to emit a synchronization event after
reporting the controller state?

Looking at drivers/input/joystick/maplecontrol.c:dc_pad_callback():

	...
	input_report_abs(dev, ABS_X,      res[12]);
	input_report_abs(dev, ABS_Y,      res[13]);
	input_report_abs(dev, ABS_RX,     res[14]);
	input_report_abs(dev, ABS_RY,     res[15]);
}

Without calling input_sync() at the end of this logical group of events,
userspace clients will not receive SYN_REPORT. Won't this cause them to
buffer events indefinitely and prevent the gamepad from functioning?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260703-b4-maple-cleanup-v1-0-41e424964da5@gmail.com?part=12