[PATCH] drm/rockchip: remove atomic helper dirtyfb

[Toni Spets]

On Thu, Feb 4, 2021, 17:20 Daniel Vetter <daniel at ffwll.ch> wrote:

> On Wed, Feb 03, 2021 at 09:53:40PM +0200, Toni Spets wrote:
> > The blocking implementation of the dirtyfb ioctl is extremely slow when
> > used for damage tracking on RK3399. If this implementation is in place
> Xorg
> > will default to using it and will slow down considerably when doing a lot
> > of small draws. This is most apparent with the fvwm window manager on
> > startup where it will almost lock up for many seconds seconds on RK3399.
> >
> > Removing this implementation did not cause any visible issues on RK3399
> but
> > it did fix the performance issues on Xorg as it will disable damage
> > tracking when the ioctl returns it's not supported.
>
> Then you don't have a manual update panel.
>
> Iirc there were patches to make this faster in recent kernels, on what
> kernels did you try this?
>

Latest was 5.10.12. If there are fixes for this in later kernels I will
definitely try it out.


> Also X should only call this in the blocker handler, not all the time.
>

It does but fvwm is an example that forces it to be called a lot and it's
slow enough to cause significant issues.


> So yeah we need to make this faster, not break manual update panels.
>

Pardon my ignorance but while making this operation faster will indeed make
it better wouldn't the correct behavior be to know if a panel requires this
or not?

Making a low performance device wait any extra time for no reason doesn't
sound like the correct fix either.

I'm not defending the patch itself as I don't have enough understanding of
the drm or kernel so if it's indeed definitely breaking something then of
course it can't be used as is.

Thanks.


-Daniel
>
> >
> > --
> > Toni Spets
>
> > From 79984ee67c801f552e9eaf4d0cfb62101d1f0f2e Mon Sep 17 00:00:00 2001
> > From: Toni Spets <toni.spets at iki.fi>
> > Date: Wed, 3 Feb 2021 21:14:50 +0200
> > Subject: [PATCH] drm/rockchip: remove atomic helper dirtyfb
> >
> > ---
> >  drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 1 -
> >  1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> > index 3aa37e177667..2554fd1c8aeb 100644
> > --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> > @@ -21,7 +21,6 @@
> >  static const struct drm_framebuffer_funcs rockchip_drm_fb_funcs = {
> >       .destroy       = drm_gem_fb_destroy,
> >       .create_handle = drm_gem_fb_create_handle,
> > -     .dirty         = drm_atomic_helper_dirtyfb,
> >  };
> >
> >  static struct drm_framebuffer *
> > --
> > 2.27.0
> >
>
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
>
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