Re: [PATCH 2/4] drm/msm/dsi: Support NO_CONNECTOR bridges
From: Laurent Pinchart
Date: Thu Aug 12 2021 - 12:44:12 EST
Hi Rob
Thank you for the patch.
On Wed, Aug 11, 2021 at 04:52:48PM -0700, Rob Clark wrote:
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
>
> For now, since we have a mix of bridges which support this flag, which
> which do *not* support this flag, or work both ways, try it once with
> NO_CONNECTOR and then fall back to the old way if that doesn't work.
> Eventually we can drop the fallback path.
>
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/Kconfig | 2 ++
> drivers/gpu/drm/msm/dsi/dsi_manager.c | 41 ++++++++++++++++++---------
> 2 files changed, 30 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
> index e9c6af78b1d7..36e5ba3ccc28 100644
> --- a/drivers/gpu/drm/msm/Kconfig
> +++ b/drivers/gpu/drm/msm/Kconfig
> @@ -14,6 +14,8 @@ config DRM_MSM
> select REGULATOR
> select DRM_KMS_HELPER
> select DRM_PANEL
> + select DRM_BRIDGE
> + select DRM_PANEL_BRIDGE
> select DRM_SCHED
> select SHMEM
> select TMPFS
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> index c41d39f5b7cf..1fd1cf93abbf 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> @@ -3,6 +3,8 @@
> * Copyright (c) 2015, The Linux Foundation. All rights reserved.
> */
>
> +#include "drm/drm_bridge_connector.h"
> +
> #include "msm_kms.h"
> #include "dsi.h"
>
> @@ -690,8 +692,7 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
> struct drm_device *dev = msm_dsi->dev;
> struct drm_encoder *encoder;
> struct drm_bridge *int_bridge, *ext_bridge;
> - struct drm_connector *connector;
> - struct list_head *connector_list;
> + int ret;
>
> int_bridge = msm_dsi->bridge;
> ext_bridge = msm_dsi->external_bridge =
> @@ -699,22 +700,36 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
>
> encoder = msm_dsi->encoder;
>
> - /* link the internal dsi bridge to the external bridge */
> - drm_bridge_attach(encoder, ext_bridge, int_bridge, 0);
> -
> /*
> - * we need the drm_connector created by the external bridge
> - * driver (or someone else) to feed it to our driver's
> - * priv->connector[] list, mainly for msm_fbdev_init()
> + * Try first to create the bridge without it creating it's own
s/it's/its/
> + * connector.. currently some bridges support this, and others
> + * do not (and some support both modes)
> */
> - connector_list = &dev->mode_config.connector_list;
> + ret = drm_bridge_attach(encoder, ext_bridge, int_bridge,
> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
Should all this be moved one layer up, to the code that attaches to the
mem_dsi->bridge ? I suppose we can start here, but as part of a global
move to bridges and DRM_BRIDGE_ATTACH_NO_CONNECTOR, I think the
top-level would make more sense in the long term.
If you want to start here,
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> + if (ret == -EINVAL) {
> + struct drm_connector *connector;
> + struct list_head *connector_list;
> +
> + /* link the internal dsi bridge to the external bridge */
> + drm_bridge_attach(encoder, ext_bridge, int_bridge, 0);
> +
> + /*
> + * we need the drm_connector created by the external bridge
> + * driver (or someone else) to feed it to our driver's
> + * priv->connector[] list, mainly for msm_fbdev_init()
> + */
> + connector_list = &dev->mode_config.connector_list;
> +
> + list_for_each_entry(connector, connector_list, head) {
> + if (drm_connector_has_possible_encoder(connector, encoder))
> + return connector;
> + }
>
> - list_for_each_entry(connector, connector_list, head) {
> - if (drm_connector_has_possible_encoder(connector, encoder))
> - return connector;
> + return ERR_PTR(-ENODEV);
> }
>
> - return ERR_PTR(-ENODEV);
> + return drm_bridge_connector_init(dev, encoder);
> }
>
> void msm_dsi_manager_bridge_destroy(struct drm_bridge *bridge)
--
Regards,
Laurent Pinchart