Re: [PATCH 1/2] regmap: add regmap_might_sleep()

[Michael Walle]

Am 2021-04-30 17:19, schrieb Mark Brown:
> On Fri, Apr 30, 2021 at 03:06:44PM +0200, Michael Walle wrote:
>
> > Sometimes a driver needs to know if the underlying regmap could sleep.
> > For example, consider the gpio-regmap driver which needs to fill the
> > gpiochip->can_sleep property.
>
> Whatever is creating the regmap really ought to know what device it's
> dealing with...

But creating and using the regmap are two seperate things, no? Consider
the gpio-sl28cpld. It will just use whatever regmap the parent has 
created.
How would it know what type of regmap it is?

> > It might be possible to pass this information via the
> > gpio_regmap_config, but this has the following drawbacks. First, that
> > property is redundant and both places might contratict each other. And
> > secondly, the driver might not even know the type of the regmap 
> > because
> > it just gets an opaque pointer by querying the device tree.
>
> If it's a generic GPIO driver from a code correctness point of view 
> it's
> always got a risk of sleeping...

I can't follow you here.

-michael