Hi Harry,
On Thu, Feb 10, 2022 at 09:38:24AM -0500, Harry Wentland wrote:
On 2022-02-10 03:42, Maxime Ripard wrote:
On Mon, Feb 07, 2022 at 01:59:38PM -0500, Harry Wentland wrote:
On 2022-02-07 13:57, Harry Wentland wrote:
On 2022-02-07 11:34, Maxime Ripard wrote:
The amdgpu KMS driver calls drm_plane_create_color_properties() with a default encoding set to BT709.
However, the core will ignore it and the driver doesn't force it in its plane state reset hook, so the initial value will be 0, which represents BT601.
Isn't this a core issue? Should __drm_atomic_helper_plane_state_reset reset all plane_state members to their properties' default values?
Ah, looks like that's exactly what you do in the later patches, which is perfect. With that, I don't think you'll need this patch anymore.
Ok, I'll squash it into the patch that removes the reset code.
I don't think that's right. I think we can just drop this patch. The amdgpu display driver is not doing BT601 by default.
My understanding from the code currently in tree is that:
1) amdgpu_dm_plane_init() will call drm_plane_create_color_properties() with an initial value set to BT709.
2) dm_drm_plane_reset() will use kzalloc and then just rely on __drm_atomic_helper_plane_reset(), which will not set the color encoding at all. It's thus 0 in the initial state.
3) the drm_color_encoding enum will have BT601 associated to 0
So it does look like the default for amdgpu at the moment is BT601?
Maxime