Re: [PATCH v3 08/22] drm/i915: Zap call to drm_plane_helper_disable.

Matt Roper
2015-05-28T01:37:27Z

On Wed, May 20, 2015 at 03:38:13PM +0200, Maarten Lankhorst wrote:
> The primary plane can still be configured when crtc is off,
> furthermore this is also a noop now that affected planes are
> added on modesets.
>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

This was added in patch #2. Can we squash this change up, or was there
a reason we needed it for the intermediate patches?

Actually, I'm not sure this is really quite a noop yet.
prepare_plane_fb is never called on the primary plane as far as I can
see, so I think our frontbuffer tracking and such might get confused.
In the regular plane update codepath, we have to handle this with a
special case by doing:

intel_crtc->atomic.disabled_planes |= (1 << drm_plane_index(plane));

in the intel_plane_atomic_check function. But from what I can see, we
bypass that in this codepath. igt/kms_universal_plane shows that we do
run into frontbuffer tracking warnings if we don't put an equivalent
update to the 'disabled_planes' flag here.

Matt

> ---
> drivers/gpu/drm/i915/intel_display.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 9e1723e20377..d738230bedf8 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12265,8 +12265,6 @@ static int __intel_set_mode(struct drm_atomic_state *state)
>
> intel_crtc_disable_planes(crtc);
> dev_priv->display.crtc_disable(crtc);
> - if (!crtc_state->enable)
> - drm_plane_helper_disable(crtc->primary);
> }
>
> /* Only after disabling all output pipelines that will be changed can we
> --
> 2.1.0
>
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--
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795