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References: <20230807133930.94309-1-andre.przywara@arm.com>
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Reply-To: wens@csie.org
From:   Chen-Yu Tsai <wens@csie.org>
Date:   Mon, 7 Aug 2023 21:56:27 +0800
Message-ID: <CAGb2v67NP0r9arrE7His6jpyb9N=yhpUUNJT3joTWAXoDRnOVw@mail.gmail.com>
Subject: Re: [PATCH] mfd: axp20x: Generalise handling without interrupts
To:     Andre Przywara <andre.przywara@arm.com>
Cc:     Lee Jones <lee@kernel.org>, linux-kernel@vger.kernel.org,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Shengyu Qu <wiagn233@outlook.com>, martin.botka1@gmail.com,
        Matthew Croughan <matthew.croughan@nix.how>
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On Mon, Aug 7, 2023 at 9:39 PM Andre Przywara <andre.przywara@arm.com> wrote:
>
> At the moment we allow the AXP15060 and the AXP806 PMICs to omit the
> interrupt line to the SoC, and we skip registering the PEK (power key)
> driver in this case, since that crashes when no IRQ is described in the
> DT node.
> The IRQ pin potentially not being connected to anything does affect more
> PMICs, though, and the PEK driver is not the only one requiring an
> interrupt: at least the AC power supply driver crashes in a similar
> fashion, for instance.
>
> Generalise the handling of AXP MFD devices when the platform tables
> describe no interrupt, by putting devices requiring an IRQ *last* in
> the MFD cell array. We then can easily cut short the number of devices
> to be registered in this case.
>
> This patch just enables that for three PMIC models for now: the two
> already handled, plus the AXP313a, for which we now have mulitple examples
> of boards without the IRQ pin connected.
> To stay consistent with the current behaviour, we still (try to) register
> all devices for the other PMICs, even though this will probably crash
> without an interrupt specified, if those problematic drivers are loaded.
> But this new approach can now easily be extended to other PMICs with more
> devices, should the need arise: currently all in-tree users are fine.
>
> This fixes operation on the first boards using the AXP313a, which do not
> bother to connect the PMIC's IRQ pin.
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> Reported-by: Shengyu Qu <wiagn233@outlook.com>

Reviewed-by: Chen-Yu Tsai <wens@csie.org>