Re: [PATCH v2] 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] Strict parsing with kstrtoul() and an early return drops packets on non-digit coordinate data, potentially causing permanently stuck touch states.
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--- Patch [1]: [PATCH v2] Input: gunze: replace deprecated APIs and fix warning style ---
commit 448e772e264a7d37aec51432b84a51cdf06f350f
Author: Bivash Kumar Singh <bivashraj750@gmail.com>

Input: gunze: replace deprecated APIs and fix warning style

This commit replaces the deprecated simple_strtoul() API with kstrtoul()
and updates the logging style to use dev_warn(). It also adds an early
return in the packet processing path if coordinate parsing fails.

> diff --git a/drivers/input/touchscreen/gunze.c b/drivers/input/touchscreen/gunze.c
> index 2baeb4f3b941c..e9c028430420c 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)
[ ... ]
> -	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';		/*NULL-terminate X portion: "1234\0" */
> +	buf[GUNZE_MAX_LENGTH] = '\0';	/*NULL-terminate Y portion */
> +
> +	if (kstrtoul(buf + 1, 10, &x) || kstrtoul(buf + 6, 10, &y))
> +		return;

[Severity: High]
Could this strict parsing with kstrtoul() and early return drop valid events
and cause the touch state to get permanently stuck?

Unlike simple_strtoul(), which stops parsing at the first non-digit character,
kstrtoul() will return an error if the string contains trailing spaces or
serial line noise.

If a touch release packet (starting with 'R') contains non-digit padding,
kstrtoul() will return an error and trigger this early return.

> +
> +	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);

Bypassing the BTN_TOUCH state update and input_sync() would cause the
touchscreen to remain stuck in a pressed state until a subsequent valid
packet is received.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260719054121.5917-1-bivashraj750@gmail.com?part=1