Re: [PATCH 02/26] Input: maple_keyb - fix key press detection

[Florian Fuchs]

On 03 Jul 22:57, Dmitry Torokhov wrote:
> The key press detection logic was using ptr instead of !ptr (where ptr is
> the result of memchr searching for the new key in the old keys).
> 
> If ptr is not NULL, it means the key was already pressed in the previous
> report, so it is not a new press. If ptr is NULL, it means the key was
> not pressed before, so it is a new press.
> 
> Using ptr instead of !ptr caused new presses to be ignored in the first
> poll cycle (only reported in the second cycle if still held, because
> then it was in 'old'), and caused redundant press events to be sent
> on every subsequent poll while the key was held.
> 
> Fix this by using !ptr for press detection, matching the release
> detection logic.
> 
> Fixes: b11d2127c489 ("Input: add support for SEGA Dreamcast keyboard")
> Assisted-by: Antigravity:gemini-3.5-flash
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> ---
>  drivers/input/keyboard/maple_keyb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/input/keyboard/maple_keyb.c b/drivers/input/keyboard/maple_keyb.c
> index 3d5538dd4f23..623d7951405b 100644
> --- a/drivers/input/keyboard/maple_keyb.c
> +++ b/drivers/input/keyboard/maple_keyb.c
> @@ -107,7 +107,7 @@ static void dc_scan_kbd(struct dc_kbd *kbd)
>  		}
>  		ptr = memchr(kbd->old + 2, kbd->new[i], 6);
>  		code = kbd->new[i];
> -		if (code > 3 && ptr) {
> +		if (code > 3 && !ptr) {
>  			keycode = kbd->keycode[code];
>  			if (keycode) {
>  				input_event(dev, EV_MSC, MSC_SCAN, code);
> 
> -- 
> 2.55.0.rc0.799.gd6f94ed593-goog
> 

Hi Dmitry,
do you want to pick this patch as well? It improves key press detection,
so would be nice.

Tested-By: Florian Fuchs <fuchsfl@xxxxxxxxx>


Regards
Florian