kernel/linux.git/drivers/gpu/drm/drm_bridge.c, branch v5.15.215

drm/bridge: Avoid uninitialized variable warning

2022-10-26T10:34:50+00:00

[ Upstream commit 7d1202738efda60155d98b370b3c70d336be0eea ] This code works, but technically it uses "num_in_bus_fmts" before it has been initialized so it leads to static checker warnings and probably KMEMsan warnings at run time. Initialize the variable to zero to silence the warning. Fixes: f32df58acc68 ("drm/bridge: Add the necessary bits to support bus format negotiation") Signed-off-by: Dan Carpenter Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/YrrIs3hoGcPVmXc5@kili Signed-off-by: Sasha Levin

drm/bridge: Move devm_drm_of_get_bridge to bridge/panel.c

2022-08-17T12:24:31+00:00

commit d4ae66f10c8b9959dce1766d9a87070e567236eb upstream. By depending on devm_drm_panel_bridge_add(), devm_drm_of_get_bridge() introduces a circular dependency between the modules drm (where devm_drm_of_get_bridge() ends up) and drm_kms_helper (where devm_drm_panel_bridge_add() is). Fix this by moving devm_drm_of_get_bridge() to bridge/panel.c and thus drm_kms_helper. Fixes: 87ea95808d53 ("drm/bridge: Add a function to abstract away panels") Reported-by: Stephen Rothwell Signed-off-by: Maxime Ripard Tested-by: Heiko Stuebner Acked-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20210917180925.2602266-1-maxime@cerno.tech Signed-off-by: Greg Kroah-Hartman

drm/bridge: Add a function to abstract away panels

2022-08-17T12:23:24+00:00

[ Upstream commit 87ea95808d53e56b03e620e8f8f3add48899a88d ] Display drivers so far need to have a lot of boilerplate to first retrieve either the panel or bridge that they are connected to using drm_of_find_panel_or_bridge(), and then either deal with each with ad-hoc functions or create a drm panel bridge through drm_panel_bridge_add. In order to reduce the boilerplate and hopefully create a path of least resistance towards using the DRM panel bridge layer, let's create the function devm_drm_of_get_bridge() to reduce that boilerplate. Signed-off-by: Maxime Ripard Reviewed-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20210910130941.1740182-2-maxime@cerno.tech Signed-off-by: Sasha Levin

drm: Fix typo in comments

2021-08-02T08:19:43+00:00

fix typo for drm v1->v2: respin with the change "iff ==> implies that" Signed-off-by: Cai Huoqing Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210730132729.376-1-caihuoqing@baidu.com

drm/bridge: Centralize error message when bridge attach fails

2021-07-28T13:33:12+00:00

Being informed of a failure to attach a bridge is useful, and many drivers prints an error message in that case. Move the message to drm_bridge_attach() to avoid code duplication. Suggested-by: Stephen Boyd Signed-off-by: Laurent Pinchart Reviewed-by: Tomi Valkeinen Reviewed-by: Jyri Sarha

drm/bridge: Fix the stop condition of drm_bridge_chain_pre_enable()

2021-04-20T15:56:44+00:00

The drm_bridge_chain_pre_enable() is not the proper opposite of drm_bridge_chain_post_disable(). It continues along the chain to _before_ the starting bridge. Let's fix that. Fixes: 05193dc38197 ("drm/bridge: Make the bridge chain a double-linked list") Signed-off-by: Douglas Anderson Reviewed-by: Andrzej Hajda Reviewed-by: Laurent Pinchart Link: https://patchwork.freedesktop.org/patch/msgid/20210416153909.v4.1.If62a003f76a2bc4ccc6c53565becc05d2aad4430@changeid

drm: bridge: Pass drm_display_info to drm_bridge_funcs .mode_valid()

2020-06-23T17:53:27+00:00

When validating a mode, bridges may need to do so in the context of a display, as specified by drm_display_info. An example is the meson dw-hdmi bridge that needs to consider the YUV 4:2:0 output format to perform clock calculations. Bridges that need the display info currently retrieve it from the drm_connector created by the bridge. This gets in the way of moving connector creation out of bridge drivers. To make this possible, pass the drm_display_info to drm_bridge_funcs .mode_valid(). Changes to the bridge drivers have been performed with the following coccinelle semantic patch and have been compile-tested. @ rule1 @ identifier funcs; identifier fn; @@ struct drm_bridge_funcs funcs = { ..., .mode_valid = fn }; @ depends on rule1 @ identifier rule1.fn; identifier bridge; identifier mode; @@ enum drm_mode_status fn( struct drm_bridge *bridge, + const struct drm_display_info *info, const struct drm_display_mode *mode ) { ... } Signed-off-by: Laurent Pinchart Reviewed-by: Neil Armstrong Reviewed-by: Boris Brezillon Reviewed-by: Guido Günther # for the nwl-dsi part: Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200526011505.31884-11-laurent.pinchart+renesas@ideasonboard.com

drm: bridge: Return NULL on error from drm_bridge_get_edid()

2020-06-23T17:52:11+00:00

The drm_bridge_get_edid() function is documented to return an error pointer on error. The underlying .get_edid() operation, however, returns NULL on error, and so do the drm_get_edid() and drm_do_get_edid() functions upon which .get_edid() is usually implemented. Make drm_bridge_get_edid() return NULL on error to be consistent. Signed-off-by: Laurent Pinchart Acked-by: Sam Ravnborg Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200526011505.31884-6-laurent.pinchart+renesas@ideasonboard.com

drm: Add helper to create a connector for a chain of bridges

2020-02-26T11:31:41+00:00

drm/bridge: Extend bridge API to disable connector creation

2020-02-26T11:31:23+00:00

Most bridge drivers create a DRM connector to model the connector at the output of the bridge. This model is historical and has worked pretty well so far, but causes several issues: - It prevents supporting more complex display pipelines where DRM connector operations are split over multiple components. For instance a pipeline with a bridge connected to the DDC signals to read EDID data, and another one connected to the HPD signal to detect connection and disconnection, will not be possible to support through this model. - It requires every bridge driver to implement similar connector handling code, resulting in code duplication. - It assumes that a bridge will either be wired to a connector or to another bridge, but doesn't support bridges that can be used in both positions very well (although there is some ad-hoc support for this in the analogix_dp bridge driver). In order to solve these issues, ownership of the connector should be moved to the display controller driver (where it can be implemented using helpers provided by the core). Extend the bridge API to allow disabling connector creation in bridge drivers as a first step towards the new model. The new flags argument to the bridge .attach() operation allows instructing the bridge driver to skip creating a connector. Unconditionally set the new flags argument to 0 for now to keep the existing behaviour, and modify all existing bridge drivers to return an error when connector creation is not requested as they don't support this feature yet. The change is based on the following semantic patch, with manual review and edits. @ rule1 @ identifier funcs; identifier fn; @@ struct drm_bridge_funcs funcs = { ..., .attach = fn }; @ depends on rule1 @ identifier rule1.fn; identifier bridge; statement S, S1; @@ int fn( struct drm_bridge *bridge + , enum drm_bridge_attach_flags flags ) { ... when != S + if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) { + DRM_ERROR("Fix bridge driver to make connector optional!"); + return -EINVAL; + } + S1 ... } @ depends on rule1 @ identifier rule1.fn; identifier bridge, flags; expression E1, E2, E3; @@ int fn( struct drm_bridge *bridge, enum drm_bridge_attach_flags flags ) { <... drm_bridge_attach(E1, E2, E3 + , flags ) ...> } @@ expression E1, E2, E3; @@ drm_bridge_attach(E1, E2, E3 + , 0 ) Signed-off-by: Laurent Pinchart Reviewed-by: Boris Brezillon Acked-by: Sam Ravnborg Reviewed-by: Tomi Valkeinen Tested-by: Sebastian Reichel Reviewed-by: Sebastian Reichel Acked-by: Daniel Vetter Signed-off-by: Tomi Valkeinen Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-10-laurent.pinchart@ideasonboard.com