Re: [PATCH] 4.15 vmgfx boot warning

[Woody Suwalski]

Sinclair Yeh wrote:
> Hi Woody,
>
> On Wed, Nov 22, 2017 at 04:05:50PM -0500, Woody Suwalski wrote:
> > The 4.15 vmwgfx driver shows a warning during boot (32 bit x86)
> > It is caused by a mismatch between the result of vmw_enable_vblank() and
> > what the drm_atomic_helper expects:
> >  ÂÂ /...
> >  ÂÂ ret = drm_crtc_vblank_get(crtc);
> >  ÂÂ WARN_ONCE(ret != -EINVAL, "driver forgot to call
> > drm_crtc_vblank_off()\n");
> This doesn't apply to us because we don't have vblank support, and so
> -ENOSYS seems to be the right error.
>
> In the commit message for 84014b0a39ee, it does state a check for this
> condition, but the check itself is based on dev->irq_enabled.
>
> Is there another way to check for vblank support?
>
>
>
> >  ÂÂ /...
> >
> > Signed-off by: Woody Suwalski <terraluna977@xxxxxxxxx>
> >
> > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.cÂÂ Â2017-11-22 15:29:46.511674079
> > -0500
> > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.cÂÂ Â2017-11-22 15:30:35.344559592
> > -0500
> > @@ -1869,7 +1869,7 @@ u32 vmw_get_vblank_counter(struct drm_de
> >  Â */
> >  Âint vmw_enable_vblank(struct drm_device *dev, unsigned int pipe)
> >  Â{
> > -ÂÂ Âreturn -ENOSYS;
> > +ÂÂ Âreturn -EINVAL;
> >  Â}
> >
> >  Â/**
Sinclair, it is a valid stand, so I guess it is time to ask Daniel...

Would it be OK to convert the WARN_ONCE statement in drm_atomic_helper 
to recognize ENOSYS as a valid error? Something like

WARN_ONCE((ret != -EINVAL && ret != _ENOSYS), "driver forgot to call 
drm_crtc_vblank_off()\n");

Thanks, Woody