[PATCH v3 00/21] drm: Add support for bus-format negotiation

[Neil Armstrong]

hi Boris,

On 23/10/2019 17:44, Boris Brezillon wrote:
> This patch series aims at adding support for runtime bus-format
> negotiation between all elements of the
> 'encoder -> bridges -> connector/display' section of the pipeline.
> 
> In order to support that, we need drm bridges to fully take part in the
> atomic state validation process, which requires adding a
> drm_bridge_state and a new drm_bridge_funcs.atomic_check() hook.
> Once those basic building blocks are in place, we can add new hooks to
> allow bus format negotiation (those are called just before
> ->atomic_check()). The bus format selection is done at runtime by
> testing all possible combinations across the whole bridge chain until
> one is reported to work.
> 
> Major changes since v2:
> * Get rid of the dummy bridge embedded in drm_encoder and let encoder
>   drivers provide their own bridge element
> * Clarify APIs and improve the doc
> * Propagate bus flags by default

Seems you forgot my reviewed-bys on patches 5, 8, 11 & 13

> 
> Major changes since the RFC:
> 
> * Add a dummy bridge to the drm_encoder object so that vc4 and exynos
>   DSI drivers can implement the pre_enable/post_disable hooks instead
>   of manually setting encoder->bridge to NULL to control the
>   enable/disable sequence. This change is also a first step towards
>   drm_bridge/drm_encoder unification. New encoder drivers should
>   stop implementing drm_encoder_helper_funcs and switch to
>   drm_bridge_funcs. Existing drivers can be converted progressively
>   (already have a branch where I started converting some of them [1])
> * rework the bus format negotiation to give more control to bridge
>   drivers in the selection process (driver can select at runtime which
>   input bus format they support for a specific output bus format based
>   on any information available in the connector, crtc and bridge state.
> 
> A more detailed changelog is provided in each patch.
> 
> This patch series is also available here [2].

Will test ASAP.

> 
> Thanks,
> 
> Boris
> 
> [1]https://github.com/bbrezillon/linux-0day/commits/drm-encoder-bridge
> [2]https://github.com/bbrezillon/linux-0day/commits/drm-bridge-busfmt-v3
> 
> *** BLURB HERE ***

Blurp

Neil

> 
> Boris Brezillon (21):
>   drm/vc4: Declare the DSI encoder as a bridge element
>   drm/exynos: Don't reset bridge->next
>   drm/exynos: Declare the DSI encoder as a bridge element
>   drm/bridge: Rename bridge helpers targeting a bridge chain
>   drm/bridge: Introduce drm_bridge_chain_get_next_bridge()
>   drm: Stop accessing encoder->bridge directly
>   drm/bridge: Make the bridge chain a double-linked list
>   drm/bridge: Add the drm_for_each_bridge_in_chain() helper
>   drm/bridge: Add a drm_bridge_state object
>   drm/bridge: Clarify the atomic enable/disable hooks semantics
>   drm/bridge: Patch atomic hooks to take a drm_bridge_state
>   drm/bridge: Add an ->atomic_check() hook
>   drm/bridge: Add the drm_bridge_chain_get_prev_bridge() helper
>   drm/bridge: Add the necessary bits to support bus format negotiation
>   drm/imx: pd: Use bus format/flags provided by the bridge when
>     available
>   drm/bridge: lvds-encoder: Implement basic bus format negotiation
>   dt-bindings: display: bridge: lvds-transmitter: Add new props
>   drm/bridge: panel: Propage bus format/flags
>   drm/panel: simple: Add support for Toshiba LTA089AC29000 panel
>   dt-bindings: display: panel: Add the LTA089AC29000 variant
>   ARM: dts: imx: imx51-zii-rdu1: Fix the display pipeline definition
> 
>  .../display/bridge/lvds-transmitter.txt       |  13 +
>  .../display/panel/toshiba,lt089ac29000.txt    |   5 +-
>  arch/arm/boot/dts/imx51-zii-rdu1.dts          |  24 +-
>  .../drm/bridge/analogix/analogix_dp_core.c    |  12 +-
>  drivers/gpu/drm/bridge/lvds-encoder.c         |  72 ++
>  drivers/gpu/drm/bridge/panel.c                |   1 +
>  drivers/gpu/drm/drm_atomic.c                  |  39 +
>  drivers/gpu/drm/drm_atomic_helper.c           |  54 +-
>  drivers/gpu/drm/drm_bridge.c                  | 800 +++++++++++++++---
>  drivers/gpu/drm/drm_encoder.c                 |  15 +-
>  drivers/gpu/drm/drm_probe_helper.c            |   4 +-
>  drivers/gpu/drm/exynos/exynos_dp.c            |   1 -
>  drivers/gpu/drm/exynos/exynos_drm_dsi.c       |  90 +-
>  drivers/gpu/drm/imx/parallel-display.c        | 174 +++-
>  drivers/gpu/drm/mediatek/mtk_hdmi.c           |   8 +-
>  drivers/gpu/drm/msm/edp/edp_bridge.c          |  10 +-
>  drivers/gpu/drm/omapdrm/omap_drv.c            |   4 +-
>  drivers/gpu/drm/omapdrm/omap_encoder.c        |   3 +-
>  drivers/gpu/drm/panel/panel-simple.c          |  36 +
>  drivers/gpu/drm/rcar-du/rcar_du_crtc.c        |  11 +-
>  drivers/gpu/drm/vc4/vc4_dsi.c                 |  90 +-
>  include/drm/drm_atomic.h                      |   3 +
>  include/drm/drm_bridge.h                      | 396 ++++++++-
>  include/drm/drm_encoder.h                     |   9 +-
>  24 files changed, 1588 insertions(+), 286 deletions(-)
>