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From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Armando De Leon <auribe84@gmail.com>
Cc: Armando De Leon <learmand@amazon.com>,
	linux-input@vger.kernel.org,  linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Input: gpio-keys - add hibernation support
Date: Mon, 6 Apr 2026 21:31:39 -0700	[thread overview]
Message-ID: <adSIEzW6wfY5rRTK@google.com> (raw)
In-Reply-To: <20260406203932.3391600-1-learmand@amazon.com>

Hi Armando,

On Mon, Apr 06, 2026 at 01:39:10PM -0700, Armando De Leon wrote:
> Hi Dmitry,
> 
> Thanks for the guidance. I investigated further:
> 
> The upstream GICv3 driver (irq-gic-v3.c) has no suspend/resume or
> syscore_ops for the distributor - it does not save or restore any
> per-IRQ configuration across power cycles. On platforms where the
> GIC is re-initialized by firmware during hibernate restore, all
> trigger type configurations set by consumer drivers during probe()
> are lost.
> 
> The IRQ core does preserve the trigger type in irq_data
> (irqd_get_trigger_type), but resume_irq() in kernel/irq/pm.c only
> re-enables the interrupt without re-applying the trigger type to
> hardware.
> 
> A fix in the IRQ PM resume path (having resume_irq() call
> irq_set_irq_type() using the saved trigger type) would fix all
> consumer drivers generically. However, such a change would have
> broad consequences and impact across all platforms and interrupt
> controllers, and would need very careful review and testing.
> 
> Given that the gpio-keys fix is a single irq_set_irq_type() call
> in the .restore callback - minimal, self-contained, and low risk -
> would it be acceptable to handle it at the driver level for now?
> This avoids the risk of a sweeping IRQ core change while solving
> the immediate problem for gpio-keys users with hibernation support.

I am sorry but as I mentioned, the proper fix is in IRQ/irqchip code,
which will ensure that not only gpio-keys but also the rest of the
consumer drivers have consistent state post hibernate.

I understand that you might need your change for a product; I recommend
applying the patch to your internal tree while you are sorting out a
generic solution.

Thanks.

-- 
Dmitry

      reply	other threads:[~2026-04-07  4:31 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-06 16:04 [PATCH] Input: gpio-keys - add hibernation support Armando De Leon
2026-04-06 16:24 ` Dmitry Torokhov
2026-04-06 16:58   ` Armando De Leon
2026-04-06 18:18     ` Dmitry Torokhov
2026-04-06 20:39   ` Armando De Leon
2026-04-07  4:31     ` Dmitry Torokhov [this message]

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