linux-kernel - Re: [RFC PATCH 3/7] regulator: IRQ based event/error notification helpers

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Message-ID: <6d6583ef2dd5fdeebc6b374de4af3f1b9d46a6c8.camel@fi.rohmeurope.com>
Date:   Mon, 15 Feb 2021 10:25:06 +0000
From:   "Vaittinen, Matti" <Matti.Vaittinen@...rohmeurope.com>
To:     "Vaittinen, Matti" <Matti.Vaittinen@...rohmeurope.com>
CC:     "agross@...nel.org" <agross@...nel.org>,
        "broonie@...nel.org" <broonie@...nel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        linux-power <linux-power@...rohmeurope.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-renesas-soc@...r.kernel.org" 
        <linux-renesas-soc@...r.kernel.org>,
        "linux-arm-msm@...r.kernel.org" <linux-arm-msm@...r.kernel.org>,
        "bjorn.andersson@...aro.org" <bjorn.andersson@...aro.org>,
        "lgirdwood@...il.com" <lgirdwood@...il.com>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>
Subject: Re: [RFC PATCH 3/7] regulator: IRQ based event/error notification
 helpers


On Thu, 2021-02-11 at 14:35 +0200, Matti Vaittinen wrote:
> Provide helper function for IC's implementing regulator notifications
> when an IRQ fires. The helper also works for IRQs which can not be
> acked.
> Helper can be set to disable the IRQ at handler and then re-enabling
> it
> on delayed work later. The helper also adds
> regulator_get_error_flags()
> errors in cache for the duration of IRQ disabling.
> 
> Signed-off-by: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
> ---
> 
> This patch has gone through only a very limited amount of testing.
> All
> reviews / suggestions / testing is highly appreciated.
> 

// Snip

> +
> +static void dev_delayed_work_drop(struct device *dev, void *res)
> +{
> +	cancel_delayed_work_sync(*(struct delayed_work **)res);
> +}
> +
> +int dev_delayed_work_autocancel(struct device *dev, struct
> delayed_work *w,
> +				void (*worker)(struct work_struct
> *work))
> +{
> +	struct delayed_work **ptr;
> +
> +	ptr = devres_alloc(dev_delayed_work_drop, sizeof(*ptr),
> GFP_KERNEL);
> +	if (!ptr)
> +		return -ENOMEM;
> +
> +	INIT_DELAYED_WORK(w, worker);
> +	*ptr = w;
> +	devres_add(dev, ptr);
> +
> +	return 0;
> +}

I sent this dev_delayed_work_autocancel() + few cleanup patches as own
series. Discussion that series created made me realize that we don't
want to force use of devm by hiding the WQ init here. We should
introduce also non devm variant + manual cancellation routine for those
who don't use devm to register rdevs.

And as I see that Greg was strongly opposing the devm based delayed
work cancellation - I guess that if we want to proceed with this one
we'd better first implement the 'non devm' variant which uses manual wq
cancellation + manual IRQ deregistering and use that cancellation to
build a devm one...

I'll try to cook v2 still this week.

Best Regards
	Matti Vaittinen