[v4,07/20] drm/colorop: Create drm_atomic_helper_colorop_create_state()
Commit Message
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 state, 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.
reset() also isn't fallible, which makes it harder to handle
initialization errors properly. This is only really relevant for some
drivers though, 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.
Continue the transition to the new pattern with drm_colorop.
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_colorop.c | 23 +++++++++++++++++++++++
include/drm/drm_colorop.h | 2 ++
2 files changed, 25 insertions(+)
Comments
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] Missing EXPORT_SYMBOL for drm_atomic_helper_colorop_create_state
- [Medium] Incomplete implementation: missing atomic_create_state hook in struct drm_colorop_funcs
--
commit 33d70aace7968630d61946321195c9263dae2576
Author: Maxime Ripard <mripard@kernel.org>
Subject: drm/colorop: Create drm_atomic_helper_colorop_create_state()
This commit introduces drm_atomic_helper_colorop_create_state() to allocate
and initialize a pristine colorop state. It is intended to separate state
initialization from hardware reset during operations like suspend and resume.
> 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.
>
> Continue the transition to the new pattern with drm_colorop.
Does this patch miss adding the new atomic_create_state hook mentioned in
the commit message?
Looking at struct drm_colorop_funcs, the atomic_create_state function
pointer does not appear to be added, and drm_colorop_reset() seems to
continue handling the state allocation directly. Does this omission cause a
regression where drivers are unable to hook into the state creation process
to subclass the colorop state?
> diff --git a/drivers/gpu/drm/drm_colorop.c b/drivers/gpu/drm/drm_colorop.c
> index 4c4d0a953e357..c0eecde8c1762 100644
> --- a/drivers/gpu/drm/drm_colorop.c
> +++ b/drivers/gpu/drm/drm_colorop.c
[ ... ]
> @@ -523,6 +523,29 @@ static void __drm_colorop_state_init(struct drm_colorop_state *colorop_state,
> }
> }
>
> +/**
> + * drm_atomic_helper_colorop_create_state - Allocates and initializes colorop atomic state
> + * @colorop: drm colorop
> + *
> + * Initializes a pristine @drm_colorop_state.
> + *
> + * RETURNS:
> + * Pointer to new colorop state, or ERR_PTR on failure.
> + */
> +struct drm_colorop_state *
> +drm_atomic_helper_colorop_create_state(struct drm_colorop *colorop)
> +{
> + struct drm_colorop_state *state;
> +
> + state = kzalloc_obj(*state);
> + if (!state)
> + return ERR_PTR(-ENOMEM);
> +
> + __drm_colorop_state_init(state, colorop);
> +
> + return state;
> +}
> +
Could the lack of an export declaration here cause a build regression for
loadable DRM modules?
Since drm_atomic_helper_colorop_create_state() is a core helper function
intended for drivers, modules attempting to reference it might encounter
unresolved symbol errors without an EXPORT_SYMBOL or EXPORT_SYMBOL_GPL
statement.
@@ -521,10 +521,33 @@ static void __drm_colorop_state_init(struct drm_colorop_state *colorop_state,
&val))
colorop_state->curve_1d_type = val;
}
}
+/**
+ * drm_atomic_helper_colorop_create_state - Allocates and initializes colorop atomic state
+ * @colorop: drm colorop
+ *
+ * Initializes a pristine @drm_colorop_state.
+ *
+ * RETURNS:
+ * Pointer to new colorop state, or ERR_PTR on failure.
+ */
+struct drm_colorop_state *
+drm_atomic_helper_colorop_create_state(struct drm_colorop *colorop)
+{
+ struct drm_colorop_state *state;
+
+ state = kzalloc_obj(*state);
+ if (!state)
+ return ERR_PTR(-ENOMEM);
+
+ __drm_colorop_state_init(state, colorop);
+
+ return state;
+}
+
/**
* __drm_colorop_reset - reset state on colorop
* @colorop: drm colorop
* @colorop_state: colorop state to assign
*
@@ -423,10 +423,12 @@ int drm_plane_colorop_3dlut_init(struct drm_device *dev, struct drm_colorop *col
struct drm_plane *plane, const struct drm_colorop_funcs *funcs,
uint32_t lut_size,
enum drm_colorop_lut3d_interpolation_type interpolation,
uint32_t flags);
+struct drm_colorop_state *
+drm_atomic_helper_colorop_create_state(struct drm_colorop *colorop);
struct drm_colorop_state *
drm_atomic_helper_colorop_duplicate_state(struct drm_colorop *colorop);
void drm_colorop_atomic_destroy_state(struct drm_colorop *colorop,
struct drm_colorop_state *state);