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.
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(-)