linux-kernel - Re: [PATCH] mfd: cpcap: Fix interrupt regression with regmap clear

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Date:   Mon, 16 Nov 2020 12:43:57 -0800
From:   Tim Harvey <tharvey@...eworks.com>
To:     Mark Brown <broonie@...nel.org>
Cc:     Lee Jones <lee.jones@...aro.org>, Tony Lindgren <tony@...mide.com>,
        open list <linux-kernel@...r.kernel.org>,
        Carl Philipp Klemm <philipp@...s.xyz>,
        Laxminath Kasam <lkasam@...eaurora.org>,
        Merlijn Wajer <merlijn@...zup.org>,
        Pavel Machek <pavel@....cz>, Sebastian Reichel <sre@...nel.org>
Subject: Re: [PATCH] mfd: cpcap: Fix interrupt regression with regmap clear_ack

On Mon, Nov 16, 2020 at 10:59 AM Mark Brown <broonie@...nel.org> wrote:
>
> On Fri, Nov 13, 2020 at 02:06:29PM -0800, Tim Harvey wrote:
>
> > asserted? I'm also wondering if my issue is that I currently have the
> > interrupt registered as such:
>
> > ret = devm_regmap_add_irq_chip(dev, gsc->regmap, client->irq,
> > IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_FALLING, 0, &gsc_irq_chip,
> > &irq_data);
>
> > Perhaps this should be IRQF_TRIGGER_LOW as the device will not
> > de-assert its IRQ# until all source bits are cleared.
>
> That's clearly an active low interrupt, it will break things if it's
> registered as edge triggered.

Mark,

Agreed - I will post a fix for my driver that changes it to IRQF_TRIGGER_LOW

What are your thoughts regarding the issue of  regmap_irq_sync_unlock
ack_invert ack'ing by writing ~d->mask_buf[i] which ends up setting
all the other bits not trying to be awk'd? I would say that the device
allowing an interrupt status to be 'set' and keeping it from releasing
its IRQ is strange/broken for sure, but I'll need to work around it
somehow.

Best Regards,

Tim