[Intel-gfx] [PATCH 10/23] drm/i915: Add gamma correction handlers

[Sharma, Shashank]

Matt, your opinion about this ? 

Regards
Shashank
-----Original Message-----
From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] On Behalf Of Daniel Vetter
Sent: Monday, September 28, 2015 12:14 PM
To: Sharma, Shashank
Cc: Daniel Vetter; Roper, Matthew D; Bish, Jim; Bradford, Robert; Smith, Gary K; dri-devel at lists.freedesktop.org; intel-gfx at lists.freedesktop.org; Matheson, Annie J; kausalmalladi at gmail.com; Vetter, Daniel
Subject: Re: [Intel-gfx] [PATCH 10/23] drm/i915: Add gamma correction handlers

On Sat, Sep 26, 2015 at 09:18:48PM +0530, Sharma, Shashank wrote:
> On 9/23/2015 1:52 PM, Sharma, Shashank wrote:
> >>Since color manager properties are meant as a new standardize KMS 
> >>extension (we put them into the core drm_crtc_state) the get/set 
> >>support should also be in the core. See e.g. how the rotation 
> >>property is handled in drm_atomic_plane_get/set_property. So all 
> >>this code should be added to drm_atomic_crtc_get/set_property.
> >Thanks, sounds like a good one. Will move this.
> Actually, while implementing this, I realized that this change is not 
> required.
> What we want to do in drm_atomic_crtc_get/set code is:
> if (prop == config->cm_palette_after_ctm_property || prop == 	
> 	config->cm_palette_before_ctm_property) {
> 	crtc->funcs->atomic_get_property();
> }
> 
> Which is already being done in the current code:
> else if (crtc->funcs->atomic_get_property)
> 	return crtc->funcs->atomic_get_property(crtc, state, property, val);

This code is to pass any property unknown to the drm core into the driver.
But since we want this to be a new drm core property set (that's why it's in drm_crtc_state) the decoding should be done in the core too.

Note that atomic_get/set_property _only_ map between the property as seen by userspace and the state structures. They're not allowed to do anything else like compute derived state, check constraints or put the state into the hw. That's for the atomic_check and atomic_commit callbacks. So for this patchset here you should move all the code in the atomic_get/set_property callbacks you add in i915 into the drm core. Like it is doen for the rotation property.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch