[PATCH v4 00/11] drm: Add support for bus-format negotiation

[Neil Armstrong]

On 03/12/2019 19:19, Laurent Pinchart wrote:
> Hi Boris,
> 
> On Tue, Dec 03, 2019 at 03:15:04PM +0100, 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.
>>
>> No Major changes in this v4. I think I addressed all comments I got
>> from Neil and Laurent (thanks for the detailed reviews BTW). Note that
>> this version only contains core changes. Once those changes are merged
>> I'll send the imx/panel/lvds-codec specific bits.
> 
> I think it would make sense to fast-track patches 01 to 07 (a bit
> selfishly as I would have a need for them in omapdrm :-)), but starting
> from 08 I wonder if it wouldn't make more sense to merge them with the
> imx/panel/lvds-codec bits to have a user.

@Boris you can push when Laurent's PR has been merged and backmerged to drm-misc-next

I have a patchset being an user of patches 8-11, so the lvds-codec stuff won't be the
only user of this !
I'll post a version ASAP to validate the v4 serie on the dw-hdmi usercase.

Thanks !

Neil

> 
>> A more detailed changelog is provided in each patch.
>>
>> This patch series is also available here [1].
>>
>> Thanks,
>>
>> Boris
>>
>> [1]https://github.com/bbrezillon/linux-0day/commits/drm-bridge-busfmt-v4
>>
>> Boris Brezillon (11):
>>   drm/bridge: Rename bridge helpers targeting a bridge chain
>>   drm/bridge: Introduce drm_bridge_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 the drm_bridge_get_prev_bridge() helper
>>   drm/bridge: Clarify the atomic enable/disable hooks semantics
>>   drm/bridge: Add a drm_bridge_state object
>>   drm/bridge: Patch atomic hooks to take a drm_bridge_state
>>   drm/bridge: Add an ->atomic_check() hook
>>   drm/bridge: Add the necessary bits to support bus format negotiation
>>
>>  .../drm/bridge/analogix/analogix_dp_core.c    |  41 +-
>>  drivers/gpu/drm/drm_atomic.c                  |  39 +
>>  drivers/gpu/drm/drm_atomic_helper.c           |  53 +-
>>  drivers/gpu/drm/drm_bridge.c                  | 756 +++++++++++++++---
>>  drivers/gpu/drm/drm_encoder.c                 |  15 +-
>>  drivers/gpu/drm/drm_probe_helper.c            |   4 +-
>>  drivers/gpu/drm/exynos/exynos_drm_dsi.c       |  13 +-
>>  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/rcar-du/rcar_du_crtc.c        |  10 +-
>>  drivers/gpu/drm/vc4/vc4_dsi.c                 |  18 +-
>>  include/drm/drm_atomic.h                      |   3 +
>>  include/drm/drm_bridge.h                      | 404 +++++++++-
>>  include/drm/drm_encoder.h                     |   7 +-
>>  16 files changed, 1174 insertions(+), 214 deletions(-)
>