On 11/29/2016 02:34 PM, Laurent Pinchart wrote:
> Instead of linking encoders and bridges in every driver (and getting it
> wrong half of the time, as many drivers forget to set the drm_bridge
> encoder pointer), do so in core code. The drm_bridge_attach() function
> needs the encoder and optional previous bridge to perform that task,
> update all the callers.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
> ---
> drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c | 4 +-
> drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 4 +-
> drivers/gpu/drm/bridge/dw-hdmi.c | 3 +-
> drivers/gpu/drm/drm_bridge.c | 46
> ++++++++++++++++------
> drivers/gpu/drm/drm_simple_kms_helper.c | 4 +-
> drivers/gpu/drm/exynos/exynos_dp.c | 5 +--
> drivers/gpu/drm/exynos/exynos_drm_dsi.c | 6 +--
> drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c | 5 +--
> drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c | 5 +--
> drivers/gpu/drm/imx/imx-ldb.c | 6 +--
> drivers/gpu/drm/imx/parallel-display.c | 4 +-
> drivers/gpu/drm/mediatek/mtk_dpi.c | 8 ++--
> drivers/gpu/drm/mediatek/mtk_dsi.c | 24 ++---------
> drivers/gpu/drm/mediatek/mtk_hdmi.c | 11 +++---
> drivers/gpu/drm/msm/dsi/dsi_manager.c | 17 +++++---
> drivers/gpu/drm/msm/edp/edp_bridge.c | 2 +-
> drivers/gpu/drm/msm/hdmi/hdmi_bridge.c | 2 +-
> drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c | 5 +--
> drivers/gpu/drm/sti/sti_dvo.c | 3 +-
> drivers/gpu/drm/sti/sti_hda.c | 3 +-
> drivers/gpu/drm/sti/sti_hdmi.c | 3 +-
> drivers/gpu/drm/sun4i/sun4i_rgb.c | 13 +++---
> include/drm/drm_bridge.h | 3 +-
> 23 files changed, 83 insertions(+), 103 deletions(-)
>
> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
> b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
> index 6119b5085501..e7799b6ee829 100644
> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
> @@ -230,9 +230,7 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device
> *dev,
> of_node_put(np);
>
> if (bridge) {
> - output->encoder.bridge = bridge;
> - bridge->encoder = &output->encoder;
> - ret = drm_bridge_attach(dev, bridge);
> + ret = drm_bridge_attach(&output->encoder, bridge, NULL);
> if (!ret)
> return 0;
> }
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index 6e0447f329a2..1835f1fdad19 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -1227,12 +1227,10 @@ static int analogix_dp_create_bridge(struct
> drm_device *drm_dev,
>
> dp->bridge = bridge;
>
> - dp->encoder->bridge = bridge;
> bridge->driver_private = dp;
> - bridge->encoder = dp->encoder;
> bridge->funcs = &analogix_dp_bridge_funcs;
>
> - ret = drm_bridge_attach(drm_dev, bridge);
> + ret = drm_bridge_attach(dp->encoder, bridge, NULL);
> if (ret) {
> DRM_ERROR("failed to attach drm bridge\n");
> return -EINVAL;
> diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c
> b/drivers/gpu/drm/bridge/dw-hdmi.c
> index b71088dab268..432e0e3fff72 100644
> --- a/drivers/gpu/drm/bridge/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/dw-hdmi.c
> @@ -1841,13 +1841,12 @@ static int dw_hdmi_register(struct drm_device *drm,
> struct dw_hdmi *hdmi)
> hdmi->bridge = bridge;
> bridge->driver_private = hdmi;
> bridge->funcs = &dw_hdmi_bridge_funcs;
> - ret = drm_bridge_attach(drm, bridge);
> + ret = drm_bridge_attach(encoder, bridge, NULL);
> if (ret) {
> DRM_ERROR("Failed to initialize bridge with drm\n");
> return -EINVAL;
> }
>
> - encoder->bridge = bridge;
> hdmi->connector.polled = DRM_CONNECTOR_POLL_HPD;
>
> drm_connector_helper_add(&hdmi->connector,
> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
> index 0ee052b7c21a..850bd6509ef1 100644
> --- a/drivers/gpu/drm/drm_bridge.c
> +++ b/drivers/gpu/drm/drm_bridge.c
> @@ -26,6 +26,7 @@
> #include <linux/mutex.h>
>
> #include <drm/drm_bridge.h>
> +#include <drm/drm_encoder.h>
>
> /**
> * DOC: overview
> @@ -92,32 +93,53 @@ void drm_bridge_remove(struct drm_bridge *bridge)
> EXPORT_SYMBOL(drm_bridge_remove);
>
> /**
> - * drm_bridge_attach - associate given bridge to our DRM device
> + * drm_bridge_attach - attach the bridge to an encoder's chain
> *
> - * @dev: DRM device
> - * @bridge: bridge control structure
> + * @encoder: DRM encoder
> + * @bridge: bridge to attach
> + * @previous: previous bridge in the chain (optional)
> *
> - * Called by a kms driver to link one of our encoder/bridge to the given
> - * bridge.
> + * Called by a kms driver to link the bridge to an encoder's chain. The
> previous
> + * argument specifies the previous bridge in the chain. If NULL, the bridge
> is
> + * linked directly at the encoder's output. Otherwise it is linked at the
> + * previous bridge's output.
> *
> - * Note that setting up links between the bridge and our encoder/bridge
> - * objects needs to be handled by the kms driver itself.
> + * If non-NULL the previous bridge must be already attached by a call to this
> + * function.
> *
> * RETURNS:
> * Zero on success, error code on failure
> */
> -int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge)
> +int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
> + struct drm_bridge *previous)
> {
> - if (!dev || !bridge)
> + int ret;
> +
> + if (!encoder || !bridge)
> + return -EINVAL;
I think we could derive previous from the encoder itself. Something like:
previous = encoder->bridge;
while (previous && previous->next)
previous = previous->next;
> +
> + if (previous && (!previous->dev || previous->encoder != encoder))
> return -EINVAL;
>
> if (bridge->dev)
> return -EBUSY;
>
> - bridge->dev = dev;
> + bridge->dev = encoder->dev;
> + bridge->encoder = encoder;
> +
> + if (bridge->funcs->attach) {
> + ret = bridge->funcs->attach(bridge);
> + if (ret < 0) {
> + bridge->dev = NULL;
> + bridge->encoder = NULL;
> + return ret;
> + }
> + }
>
> - if (bridge->funcs->attach)
> - return bridge->funcs->attach(bridge);
> + if (previous)
> + previous->next = bridge;
> + else
> + encoder->bridge = bridge;
>
> return 0;
> }
<snip>
Archit
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