Re: [PATCH v3] Input: gunze: replace deprecated APIs and fix warning style

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The newly added early return on coordinate parsing failure drops critical touch state transitions (like touch releases), causing stuck touches.
--

--- Patch [1]: [PATCH v3] Input: gunze: replace deprecated APIs and fix warning style ---
commit 7585c5c9a9ed51c8709aeaa8875aeb5e7e1646b2
Author: Bivash Kumar Singh <bivashraj750@gmail.com>

Input: gunze: replace deprecated APIs and fix warning style

This commit replaces deprecated simple_strtoul calls with kstrtoul and adds an
early return for parsing failures. It also updates the logging from printk to
dev_warn using the serio device.

> diff --git a/drivers/input/touchscreen/gunze.c b/drivers/input/touchscreen/gunze.c
> index 2baeb4f3b941c..0e8131cad647e 100644
> --- a/drivers/input/touchscreen/gunze.c
> +++ b/drivers/input/touchscreen/gunze.c
> @@ -41,15 +41,24 @@ static void gunze_process_packet(struct gunze *gunze)
>  {
>  	struct input_dev *dev = gunze->dev;
> +	char buf[GUNZE_MAX_LENGTH + 1];
> +	unsigned long x, y;
>  
>  	if (gunze->idx != GUNZE_MAX_LENGTH || gunze->data[5] != ',' ||
>  		(gunze->data[0] != 'T' && gunze->data[0] != 'R')) {
> -		printk(KERN_WARNING "gunze.c: bad packet: >%.*s<\n", GUNZE_MAX_LENGTH, gunze->data);
> +		dev_warn(&gunze->serio->dev, "bad packet: >%.*s<\n", GUNZE_MAX_LENGTH, gunze->data);
>  		return;
>  	}
>  
> -	input_report_abs(dev, ABS_X, simple_strtoul(gunze->data + 1, NULL, 10));
> -	input_report_abs(dev, ABS_Y, 1024 - simple_strtoul(gunze->data + 6, NULL, 10));
> +	memcpy(buf, gunze->data, GUNZE_MAX_LENGTH);
> +	buf[5] = '\0';		/* NUL-terminate X portion: "1234\0" */
> +	buf[GUNZE_MAX_LENGTH] = '\0';	/* NUL-terminate Y portion */
> +
> +	if (kstrtoul(buf + 1, 10, &x) || kstrtoul(buf + 6, 10, &y))
> +		return;

[Severity: High]
Does this early return risk dropping critical touch state transitions, such as
touch releases, causing stuck touches?

If a release packet ('R') contains unparseable coordinates (such as space
padding or noise), parsing will fail and trigger this early return.

Because the return bypasses the input_report_key call for BTN_TOUCH and the
subsequent input_sync call, the release event would be silently dropped.

Could this leave the touchscreen desynchronized and permanently stuck in the
pressed state?

> +
> +	input_report_abs(dev, ABS_X, x);
> +	input_report_abs(dev, ABS_Y, 1024 - y);
>  	input_report_key(dev, BTN_TOUCH, gunze->data[0] == 'T');
>  	input_sync(dev);
>  }

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260719060238.6440-1-bivashraj750@gmail.com?part=1