[PATCH v2 10/20] drm/crtc: Add new atomic_create_state callback

[Dmitry Baryshkov]

On Fri, Mar 20, 2026 at 05:27:17PM +0100, Maxime Ripard wrote:
> Commit 47b5ac7daa46 ("drm/atomic: Add new atomic_create_state callback
> to drm_private_obj") introduced a new pattern for allocating drm object
> states.
> 
> Instead of relying on the reset() callback, it created a new
> atomic_create_state hook. This is helpful because reset is a bit
> overloaded: it's used to create the initial software tate, reset it, but
> also reset the hardware.
> 
> It can also be used either at probe time, to create the initial state
> and possibly reset the hardware to an expected default, but also during
> suspend/resume.
> 
> Both these cases come with different expectations too: during the
> initialization, we want to initialize all states, but during
> suspend/resume, drm_private_states for example are expected to be kept
> around.
> 
> And reset() isn't fallible, which makes it harder to handle
> initialization errors properly.
> 
> And this is only really relevant for some drivers, since all the helpers
> for reset only create a new state, and don't touch the hardware at all.
> 
> It was thus decided to create a new hook that would allocate and
> initialize a pristine state without any side effect:
> atomic_create_state to untangle a bit some of it, and to separate the
> initialization with the actual reset one might need during a
> suspend/resume.
> 
> Let's continue the transition to the new pattern with crtcs.
> 
> Signed-off-by: Maxime Ripard <mripard at kernel.org>
> ---
>  drivers/gpu/drm/drm_atomic_state_helper.c | 47 +++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_mode_config.c         | 21 +++++++++++++-
>  include/drm/drm_atomic_state_helper.h     |  4 +++
>  include/drm/drm_crtc.h                    | 13 +++++++++
>  4 files changed, 84 insertions(+), 1 deletion(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at oss.qualcomm.com>


-- 
With best wishes
Dmitry