[RFC PATCH v3 1/3] drm: Introduce solid fill property for drm plane

Harry Wentland harry.wentland at amd.com
Thu Jan 19 16:27:33 UTC 2023



On 1/19/23 11:24, Jessica Zhang wrote:
> 
> 
> On 1/19/2023 7:57 AM, Harry Wentland wrote:
>>
>>
>> On 1/18/23 17:53, Jessica Zhang wrote:
>>>
>>>
>>> On 1/18/2023 10:57 AM, Harry Wentland wrote:
>>>> On 1/4/23 18:40, Jessica Zhang wrote:
>>>>> Add support for solid_fill property to drm_plane. In addition, add
>>>>> support for setting and getting the values for solid_fill.
>>>>>
>>>>> solid_fill holds data for supporting solid fill planes. The property
>>>>> accepts an RGB323232 value and the driver data is formatted as such:
>>>>>
>>>>> struct drm_solid_fill {
>>>>>      u32 r;
>>>>>      u32 g;
>>>>>      u32 b;
>>>>> };
>>>>
>>>> Rather than special-casing this would it make sense to define this
>>>> as a single pixel of a FOURCC property?
>>>>
>>>> I.e., something like this:
>>>>
>>>> struct drm_solid_fill_info {
>>>>      u32 format; /* FOURCC value */
>>>>      u64 value; /* FOURCC pixel value */
>>>> }
>>>>
>>>> That removes some ambiguity how the value should be interpreted, i.e.,
>>>> it can be interpreted like a single pixel of the specified FOURCC format.
>>>>
>>>> It might also make sense to let drivers advertise the supported
>>>> FOURCC formats for solid_fill planes.
>>>
>>> Hi Harry,
>>>
>>> The initial v1 of this RFC had support for taking in a format and such, but it was decided that just supporting RGB323232 would work too.
>>>
>>> Here's the original thread discussing it [1], but to summarize, the work needed to convert the solid fill color to RGB is trivial (as it's just a single pixel of data). In addition, supporting various formats for solid_fill would add complexity as we'd have to communicate which formats are supported.
>>>
>>> [1] https://lists.freedesktop.org/archives/dri-devel/2022-November/379148.html
>>>
>>
>> Make sense, and thanks for summarizing.
>>
>> The only comment I would have left then, is that maybe it'd be good to add
>> an alpha value. I think it was suggested by someone else as well.
> 
> Yep it was mentioned in the v1 discussion, but we came to the conclusion that user can set the alpha through the separate alpha plane property.
> 

Got it.

Harry

> Thanks,
> 
> Jessica Zhang
> 
>>
>>>>
>>>> Is there an implementation for this in a corresponding canonical
>>>> upstream userspace project, to satisfy [1]? If not, what is the plan
>>>> for this? If so, please point to the corresponding patches.
>>>
>>> The use case we're trying to support here is the Android HWC SOLID_FILL hint [1], though it can also be used to address the Wayland single pixel FB protocol [2]. I'm also planning to add an IGT test to show an example of end to end usage.
>>>
>>> [1] https://android.googlesource.com/platform/hardware/interfaces/+/refs/heads/master/graphics/composer/aidl/android/hardware/graphics/composer3/Composition.aidl#52
>>>
>>> [2] https://gitlab.freedesktop.org/wayland/wayland-protocols/-/merge_requests/104
>>>
>>
>> Makes sense.
>>
>> Harry
>>
>>> Thanks,
>>>
>>> Jessica Zhang
>>>
>>>>
>>>> [1] https://dri.freedesktop.org/docs/drm/gpu/drm-uapi.html#open-source-userspace-requirements
>>>>
>>>> Harry
>>>>
>>>>>
>>>>> To enable solid fill planes, userspace must assigned solid_fill to a
>>>>> property blob containing the following information:
>>>>>
>>>>> struct drm_solid_fill_info {
>>>>>      u8 version;
>>>>>      u32 r, g, b;
>>>>> };
>>>>>
>>>>> Changes in V2:
>>>>> - Changed solid_fill property to a property blob (Simon, Dmitry)
>>>>> - Added drm_solid_fill struct (Simon)
>>>>> - Added drm_solid_fill_info struct (Simon)
>>>>>
>>>>> Changes in V3:
>>>>> - Corrected typo in drm_solid_fill struct documentation
>>>>>
>>>>> Signed-off-by: Jessica Zhang <quic_jesszhan at quicinc.com>
>>>>> ---
>>>>>    drivers/gpu/drm/drm_atomic_state_helper.c |  9 ++++
>>>>>    drivers/gpu/drm/drm_atomic_uapi.c         | 59 +++++++++++++++++++++++
>>>>>    drivers/gpu/drm/drm_blend.c               | 17 +++++++
>>>>>    include/drm/drm_blend.h                   |  1 +
>>>>>    include/drm/drm_plane.h                   | 43 +++++++++++++++++
>>>>>    5 files changed, 129 insertions(+)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
>>>>> index dfb57217253b..c96fd1f2ad99 100644
>>>>> --- a/drivers/gpu/drm/drm_atomic_state_helper.c
>>>>> +++ b/drivers/gpu/drm/drm_atomic_state_helper.c
>>>>> @@ -253,6 +253,11 @@ void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
>>>>>        plane_state->alpha = DRM_BLEND_ALPHA_OPAQUE;
>>>>>        plane_state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;
>>>>>    +    if (plane_state->solid_fill_blob) {
>>>>> +        drm_property_blob_put(plane_state->solid_fill_blob);
>>>>> +        plane_state->solid_fill_blob = NULL;
>>>>> +    }
>>>>> +
>>>>>        if (plane->color_encoding_property) {
>>>>>            if (!drm_object_property_get_default_value(&plane->base,
>>>>>                                   plane->color_encoding_property,
>>>>> @@ -335,6 +340,9 @@ void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
>>>>>        if (state->fb)
>>>>>            drm_framebuffer_get(state->fb);
>>>>>    +    if (state->solid_fill_blob)
>>>>> +        drm_property_blob_get(state->solid_fill_blob);
>>>>> +
>>>>>        state->fence = NULL;
>>>>>        state->commit = NULL;
>>>>>        state->fb_damage_clips = NULL;
>>>>> @@ -384,6 +392,7 @@ void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
>>>>>            drm_crtc_commit_put(state->commit);
>>>>>          drm_property_blob_put(state->fb_damage_clips);
>>>>> +    drm_property_blob_put(state->solid_fill_blob);
>>>>>    }
>>>>>    EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
>>>>>    diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
>>>>> index c06d0639d552..8a1d2fb7a757 100644
>>>>> --- a/drivers/gpu/drm/drm_atomic_uapi.c
>>>>> +++ b/drivers/gpu/drm/drm_atomic_uapi.c
>>>>> @@ -316,6 +316,55 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
>>>>>    }
>>>>>    EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector);
>>>>>    +static void drm_atomic_convert_solid_fill_info(struct drm_solid_fill *out,
>>>>> +        struct drm_solid_fill_info *in)
>>>>> +{
>>>>> +    out->r = in->r;
>>>>> +    out->g = in->g;
>>>>> +    out->b = in->b;
>>>>> +}
>>>>> +
>>>>> +static int drm_atomic_set_solid_fill_prop(struct drm_plane_state *state,
>>>>> +        struct drm_property_blob *blob)
>>>>> +{
>>>>> +    int ret = 0;
>>>>> +    int blob_version;
>>>>> +
>>>>> +    if (blob == state->solid_fill_blob)
>>>>> +        return 0;
>>>>> +
>>>>> +    drm_property_blob_put(state->solid_fill_blob);
>>>>> +    state->solid_fill_blob = NULL;
>>>>> +
>>>>> +    memset(&state->solid_fill, 0, sizeof(state->solid_fill));
>>>>> +
>>>>> +    if (blob) {
>>>>> +        if (blob->length != sizeof(struct drm_solid_fill_info)) {
>>>>> +            drm_dbg_atomic(state->plane->dev,
>>>>> +                    "[PLANE:%d:%s] bad solid fill blob length: %zu\n",
>>>>> +                    state->plane->base.id, state->plane->name,
>>>>> +                    blob->length);
>>>>> +            return -EINVAL;
>>>>> +        }
>>>>> +
>>>>> +        blob_version = ((struct drm_solid_fill_info *)blob->data)->version;
>>>>> +
>>>>> +        /* Append with more versions if necessary */
>>>>> +        if (blob_version == 1) {
>>>>> +            drm_atomic_convert_solid_fill_info(&state->solid_fill, blob->data);
>>>>> +        } else {
>>>>> +            drm_dbg_atomic(state->plane->dev,
>>>>> +                    "[PLANE:%d:%s] failed to set solid fill (ret=%d)\n",
>>>>> +                    state->plane->base.id, state->plane->name,
>>>>> +                    ret);
>>>>> +            return -EINVAL;
>>>>> +        }
>>>>> +        state->solid_fill_blob = drm_property_blob_get(blob);
>>>>> +    }
>>>>> +
>>>>> +    return ret;
>>>>> +}
>>>>> +
>>>>>    static void set_out_fence_for_crtc(struct drm_atomic_state *state,
>>>>>                       struct drm_crtc *crtc, s32 __user *fence_ptr)
>>>>>    {
>>>>> @@ -544,6 +593,13 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane,
>>>>>            state->src_w = val;
>>>>>        } else if (property == config->prop_src_h) {
>>>>>            state->src_h = val;
>>>>> +    } else if (property == plane->solid_fill_property) {
>>>>> +        struct drm_property_blob *solid_fill = drm_property_lookup_blob(dev, val);
>>>>> +
>>>>> +        ret = drm_atomic_set_solid_fill_prop(state, solid_fill);
>>>>> +        drm_property_blob_put(solid_fill);
>>>>> +
>>>>> +        return ret;
>>>>>        } else if (property == plane->alpha_property) {
>>>>>            state->alpha = val;
>>>>>        } else if (property == plane->blend_mode_property) {
>>>>> @@ -616,6 +672,9 @@ drm_atomic_plane_get_property(struct drm_plane *plane,
>>>>>            *val = state->src_w;
>>>>>        } else if (property == config->prop_src_h) {
>>>>>            *val = state->src_h;
>>>>> +    } else if (property == plane->solid_fill_property) {
>>>>> +        *val = state->solid_fill_blob ?
>>>>> +            state->solid_fill_blob->base.id : 0;
>>>>>        } else if (property == plane->alpha_property) {
>>>>>            *val = state->alpha;
>>>>>        } else if (property == plane->blend_mode_property) {
>>>>> diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c
>>>>> index b4c8cab7158c..17ab645c8309 100644
>>>>> --- a/drivers/gpu/drm/drm_blend.c
>>>>> +++ b/drivers/gpu/drm/drm_blend.c
>>>>> @@ -616,3 +616,20 @@ int drm_plane_create_blend_mode_property(struct drm_plane *plane,
>>>>>        return 0;
>>>>>    }
>>>>>    EXPORT_SYMBOL(drm_plane_create_blend_mode_property);
>>>>> +
>>>>> +int drm_plane_create_solid_fill_property(struct drm_plane *plane)
>>>>> +{
>>>>> +    struct drm_property *prop;
>>>>> +
>>>>> +    prop = drm_property_create(plane->dev,
>>>>> +            DRM_MODE_PROP_ATOMIC | DRM_MODE_PROP_BLOB,
>>>>> +            "solid_fill", 0);
>>>>> +    if (!prop)
>>>>> +        return -ENOMEM;
>>>>> +
>>>>> +    drm_object_attach_property(&plane->base, prop, 0);
>>>>> +    plane->solid_fill_property = prop;
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +EXPORT_SYMBOL(drm_plane_create_solid_fill_property);
>>>>> diff --git a/include/drm/drm_blend.h b/include/drm/drm_blend.h
>>>>> index 88bdfec3bd88..0338a860b9c8 100644
>>>>> --- a/include/drm/drm_blend.h
>>>>> +++ b/include/drm/drm_blend.h
>>>>> @@ -58,4 +58,5 @@ int drm_atomic_normalize_zpos(struct drm_device *dev,
>>>>>                      struct drm_atomic_state *state);
>>>>>    int drm_plane_create_blend_mode_property(struct drm_plane *plane,
>>>>>                         unsigned int supported_modes);
>>>>> +int drm_plane_create_solid_fill_property(struct drm_plane *plane);
>>>>>    #endif
>>>>> diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
>>>>> index 447e664e49d5..3b9da06f358b 100644
>>>>> --- a/include/drm/drm_plane.h
>>>>> +++ b/include/drm/drm_plane.h
>>>>> @@ -40,6 +40,25 @@ enum drm_scaling_filter {
>>>>>        DRM_SCALING_FILTER_NEAREST_NEIGHBOR,
>>>>>    };
>>>>>    +/**
>>>>> + * struct drm_solid_fill_info - User info for solid fill planes
>>>>> + */
>>>>> +struct drm_solid_fill_info {
>>>>> +    __u8 version;
>>>>> +    __u32 r, g, b;
>>>>> +};
>>>>> +
>>>>> +/**
>>>>> + * struct solid_fill_property - RGB values for solid fill plane
>>>>> + *
>>>>> + * Note: This is the V1 for this feature
>>>>> + */
>>>>> +struct drm_solid_fill {
>>>>> +    uint32_t r;
>>>>> +    uint32_t g;
>>>>> +    uint32_t b;
>>>>> +};
>>>>> +
>>>>>    /**
>>>>>     * struct drm_plane_state - mutable plane state
>>>>>     *
>>>>> @@ -116,6 +135,23 @@ struct drm_plane_state {
>>>>>        /** @src_h: height of visible portion of plane (in 16.16) */
>>>>>        uint32_t src_h, src_w;
>>>>>    +    /**
>>>>> +     * @solid_fill_blob:
>>>>> +     *
>>>>> +     * Blob containing relevant information for a solid fill plane
>>>>> +     * including pixel format and data. See
>>>>> +     * drm_plane_create_solid_fill_property() for more details.
>>>>> +     */
>>>>> +    struct drm_property_blob *solid_fill_blob;
>>>>> +
>>>>> +    /**
>>>>> +     * @solid_fill:
>>>>> +     *
>>>>> +     * Pixel data for solid fill planes. See
>>>>> +     * drm_plane_create_solid_fill_property() for more details.
>>>>> +     */
>>>>> +    struct drm_solid_fill solid_fill;
>>>>> +
>>>>>        /**
>>>>>         * @alpha:
>>>>>         * Opacity of the plane with 0 as completely transparent and 0xffff as
>>>>> @@ -699,6 +735,13 @@ struct drm_plane {
>>>>>         */
>>>>>        struct drm_plane_state *state;
>>>>>    +    /*
>>>>> +     * @solid_fill_property:
>>>>> +     * Optional solid_fill property for this plane. See
>>>>> +     * drm_plane_create_solid_fill_property().
>>>>> +     */
>>>>> +    struct drm_property *solid_fill_property;
>>>>> +
>>>>>        /**
>>>>>         * @alpha_property:
>>>>>         * Optional alpha property for this plane. See
>>>>
>>



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