From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Paul Cercueil <paul@crapouillou.net>
Cc: od@zcrc.me, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/3] input: gpio-keys: Use hrtimer for software debounce, if possible
Date: Tue, 23 Mar 2021 14:34:32 -0700 [thread overview]
Message-ID: <YFpe6EhydawiMjHB@google.com> (raw)
In-Reply-To: <20210307222240.380583-3-paul@crapouillou.net>
On Sun, Mar 07, 2021 at 10:22:40PM +0000, Paul Cercueil wrote:
> We want to be able to report the input event as soon as the debounce
> delay elapsed. However, the current code does not really ensure that,
> as it uses the jiffies-based schedule_delayed_work() API. With a small
> enough HZ value (HZ <= 100), this results in some input events being
> lost, when a key is quickly pressed then released (on a human's time
> scale).
>
> Switching to hrtimers fixes this issue, and will work even on extremely
> low HZ values (tested at HZ=24). This is however only possible if
> reading the GPIO is possible without sleeping. If this condition is not
> met, the previous approach of using a jiffies-based timer is taken.
>
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Applied with minor edits to make more use of debounce_use_hrtimer flag.
Thanks.
--
Dmitry
next prev parent reply other threads:[~2021-03-23 21:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-07 22:22 [PATCH v3 1/3] input: gpio-keys: Remove extra call to input_sync Paul Cercueil
2021-03-07 22:22 ` [PATCH v3 2/3] input: gpio-keys: Use hrtimer for release timer Paul Cercueil
2021-03-23 21:33 ` Dmitry Torokhov
2021-03-07 22:22 ` [PATCH v3 3/3] input: gpio-keys: Use hrtimer for software debounce, if possible Paul Cercueil
2021-03-23 21:34 ` Dmitry Torokhov [this message]
2021-04-06 8:37 ` Tony Lindgren
2021-04-07 4:34 ` Dmitry Torokhov
2021-03-23 21:33 ` [PATCH v3 1/3] input: gpio-keys: Remove extra call to input_sync Dmitry Torokhov
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