Re: [PATCH v3 1/3] drm/v3d: Add support for V3D v4.2.

[Dave Emett]

On Fri, 8 Mar 2019 at 16:51, Eric Anholt <eric@xxxxxxxxxx> wrote:
>
> Dave Emett <david.emett@xxxxxxxxxxxx> writes:
>
> > Sorry, a few things I thought of after sending the Reviewed-by email...
> >
> >> +       v3d->reset = devm_reset_control_get_exclusive(dev, NULL);
> >> +       if (IS_ERR(v3d->reset)) {
> >> +               ret = PTR_ERR(v3d->reset);
> >> +
> >> +               if (ret == -EPROBE_DEFER)
> >> +                       goto dev_free;
> > Might be preferable to make this explicitly check against the
> > not-found error code (whatever that is)? As in if (not found)
> > <fallback to bridge> else <return error code>. Similarly...
>
> You won't have both a bridge and an external reset controller in the DT,
> so I'm not clear on what functional change you're looking for.  You're
> just concerned about what the return code from this function is?
> -EPROBE_DEFER is the only one that matters from a probe, really.

I don't think it matters here. I just figured it should probably be
done the same way as the IRQ.

> >> +       if (platform_get_irq(v3d->pdev, 1) < 0) {
> > This should probably explicitly check for not-found rather than any
> > error. As-is, we might silently go down the single-interrupt-line path
> > on a platform with 2 interrupt lines if platform_get_irq(v3d->pdev, 1)
> > hits some other error.
>
> If I do the -EPROBE_DEFER check here, will that be good enough for you?

If that's the only other error we can get then sure. It wasn't clear
to me what errors might be returned from platform_get_irq.