On Sat, 9 Apr 2022 at 03:54, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
>
> For vendors drivers which pass an already allocated and
> initialized encoder especially for cases where the encoder
> hardware is shared OR the writeback encoder shares the resources
> with the rest of the display pipeline introduce a new API,
> drm_writeback_connector_init_with_encoder() which expects
> an initialized encoder as a parameter and only sets up the
> writeback connector.
>
> changes in v4:
> - removed the possible_crtcs part
>
> changes in v5:
> - reorder this change to come before in the series
> to avoid incorrect functionality in subsequent changes
> - continue using struct drm_encoder instead of
> struct drm_encoder * and switch it in next change
>
> changes in v6:
> - remove drm_writeback_connector_setup() and instead
> directly call drm_writeback_connector_init_with_encoder()
> - fix a drm_writeback_connector typo and function doc which
> incorrectly shows that the function accepts enc_helper_funcs
> - pass encoder as a parameter explicitly to the new API
> for better readability
>
> changes in v7:
> - fix the function doc slightly as suggested by Liviu
>
> Reviewed-by: Liviu Dudau <liviu.dudau@xxxxxxx>
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_writeback.c | 72 +++++++++++++++++++++++++++++++++--------
> include/drm/drm_writeback.h | 6 ++++
> 2 files changed, 64 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
> index 9e0b845..92658ad 100644
> --- a/drivers/gpu/drm/drm_writeback.c
> +++ b/drivers/gpu/drm/drm_writeback.c
> @@ -178,6 +178,62 @@ int drm_writeback_connector_init(struct drm_device *dev,
> const u32 *formats, int n_formats,
> u32 possible_crtcs)
> {
> + int ret = 0;
> +
> + drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
> +
> + wb_connector->encoder.possible_crtcs = possible_crtcs;
> +
> + ret = drm_encoder_init(dev, &wb_connector->encoder,
> + &drm_writeback_encoder_funcs,
> + DRM_MODE_ENCODER_VIRTUAL, NULL);
> + if (ret)
> + return ret;
> +
> + ret = drm_writeback_connector_init_with_encoder(dev, wb_connector, &wb_connector->encoder,
> + con_funcs, formats, n_formats);
> +
> + if (ret)
> + drm_encoder_cleanup(&wb_connector->encoder);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_writeback_connector_init);
> +
> +/**
> + * drm_writeback_connector_init_with_encoder - Initialize a writeback connector and its properties
> + * using the encoder which already assigned and initialized
> + *
> + * @dev: DRM device
> + * @wb_connector: Writeback connector to initialize
> + * @enc: handle to the already initialized drm encoder
> + * @con_funcs: Connector funcs vtable
> + * @formats: Array of supported pixel formats for the writeback engine
> + * @n_formats: Length of the formats array
> + *
> + * This function creates the writeback-connector-specific properties if they
> + * have not been already created, initializes the connector as
> + * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
> + * values.
> + *
> + * This function assumes that the drm_writeback_connector's encoder has already been
> + * created and initialized before invoking this function.
> + *
> + * In addition, this function also assumes that callers of this API will manage
> + * assigning the encoder helper functions, possible_crtcs and any other encoder
> + * specific operation.
> + *
> + * Drivers should always use this function instead of drm_connector_init() to
> + * set up writeback connectors if they want to manage themselves the lifetime of the
> + * associated encoder.
> + *
> + * Returns: 0 on success, or a negative error code
> + */
> +int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
> + struct drm_writeback_connector *wb_connector, struct drm_encoder *enc,
> + const struct drm_connector_funcs *con_funcs, const u32 *formats,
> + int n_formats)
> +{
> struct drm_property_blob *blob;
> struct drm_connector *connector = &wb_connector->base;
> struct drm_mode_config *config = &dev->mode_config;
> @@ -191,15 +247,6 @@ int drm_writeback_connector_init(struct drm_device *dev,
> if (IS_ERR(blob))
> return PTR_ERR(blob);
>
> - drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
> -
> - wb_connector->encoder.possible_crtcs = possible_crtcs;
> -
> - ret = drm_encoder_init(dev, &wb_connector->encoder,
> - &drm_writeback_encoder_funcs,
> - DRM_MODE_ENCODER_VIRTUAL, NULL);
> - if (ret)
> - goto fail;
>
> connector->interlace_allowed = 0;
>
> @@ -208,8 +255,7 @@ int drm_writeback_connector_init(struct drm_device *dev,
> if (ret)
> goto connector_fail;
>
> - ret = drm_connector_attach_encoder(connector,
> - &wb_connector->encoder);
> + ret = drm_connector_attach_encoder(connector, enc);
> if (ret)
> goto attach_fail;
>
> @@ -238,12 +284,10 @@ int drm_writeback_connector_init(struct drm_device *dev,
> attach_fail:
> drm_connector_cleanup(connector);
> connector_fail:
> - drm_encoder_cleanup(&wb_connector->encoder);
> -fail:
> drm_property_blob_put(blob);
> return ret;
> }
> -EXPORT_SYMBOL(drm_writeback_connector_init);
> +EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder);
>
> int drm_writeback_set_fb(struct drm_connector_state *conn_state,
> struct drm_framebuffer *fb)
> diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
> index 5d9263f..bb306fa 100644
> --- a/include/drm/drm_writeback.h
> +++ b/include/drm/drm_writeback.h
> @@ -153,6 +153,12 @@ int drm_writeback_connector_init(struct drm_device *dev,
> const u32 *formats, int n_formats,
> u32 possible_crtcs);
>
> +int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
> + struct drm_writeback_connector *wb_connector,
> + struct drm_encoder *enc,
> + const struct drm_connector_funcs *con_funcs, const u32 *formats,
> + int n_formats);
> +
> int drm_writeback_set_fb(struct drm_connector_state *conn_state,
> struct drm_framebuffer *fb);
>
> --
> 2.7.4
>
--
With best wishes
Dmitry
