mainline/master boot bisection: v4.15-rc3 on peach-pi #3228-staging

[linux@armlinux.org.uk (Russell King - ARM Linux)]

On Mon, Dec 11, 2017 at 10:58:29PM +0000, Russell King - ARM Linux wrote:
> On Mon, Dec 11, 2017 at 11:54:48PM +0100, Javier Martinez Canillas wrote:
> > So I gave a quick look to this, and at the very least there's a bug in
> > the Exynos5800 Peach Pi DTS caused by commit 1cb686c08d12 ("ARM: dts:
> > exynos: Add status property to Exynos 542x Mixer nodes").
> > 
> > I've posted a fix for that:
> > 
> > https://patchwork.kernel.org/patch/10105921/
> > 
> > I believe this could be also be the cause for the boot failure, since
> > I see in the boot log that things start to go wrong after exynos-drm
> > fails to bind the HDMI component:
> > 
> > [ 2.916347] exynos-drm exynos-drm: failed to bind 14530000.hdmi (ops
> > 0xc1398690): -1
> 
> Umm, -1 ?  Looking that error code up in
> include/uapi/asm-generic/errno-base.h says it's -EPERM.
> 
> I suspect that's someone just returning -1 because they're lazy...
> which is real bad form and needs fixing.

Oh, it really is -EPERM:

struct exynos_drm_crtc *exynos_drm_crtc_get_by_type(struct drm_device *drm_dev,
                                       enum exynos_drm_output_type out_type)
{
        struct drm_crtc *crtc;

        drm_for_each_crtc(crtc, drm_dev)
                if (to_exynos_crtc(crtc)->type == out_type)
                        return to_exynos_crtc(crtc);

        return ERR_PTR(-EPERM);
}

Does "Operation not permitted" really convey the error here?  It doesn't
look like a permission error to me.

Can we please avoid abusing errno codes?

-- 
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