linux-kernel - Re: [PATCH v2] pinctrl: sunxi: set minimal debounce on input-debounce 0

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Date:   Mon, 13 Feb 2023 09:45:25 +0100
From:   Maxime Ripard <maxime@...no.tech>
To:     Andreas Feldner <pelzi@...ing-snail.de>
Cc:     Andre Przywara <andre.przywara@....com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Chen-Yu Tsai <wens@...e.org>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        Samuel Holland <samuel@...lland.org>,
        linux-gpio@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-sunxi@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] pinctrl: sunxi: set minimal debounce on
 input-debounce 0

Hi,

On Sun, Feb 12, 2023 at 07:21:03PM +0100, Andreas Feldner wrote:
> sunxi-h3-h5 based boards have no support for switching
> off IRQ debouncing filter. This would be the expected
> behaviour of value 0 for the general pinctl parameter
> input-debounce.
> The current driver implementation ignores value 0
> for input-debounce, leaving the chip's default. This
> default, however, is not minimal, but equivalent to
> value 31 (microseconds).
> 
> This patch does not ignore value 0 but instead makes
> sure the corresponding IRQ debounce filter is set
> to the shortest time selectable, i. e. the fast
> oscillator with a divider of 1 == (2 ^ 0).
> 
> Fixes: 7c926492d38a ("pinctrl: sunxi: Add support for interrupt debouncing")
> 
> Signed-off-by: Andreas Feldner <pelzi@...ing-snail.de>

Like I said in the other thread, I don't think that deviating from the
generic property semantics is a good thing.

Maxime