[PATCH v8 00/39] Add HDMI 2.0 support to DW HDMI QP TX
Cristian Ciocaltea
cristian.ciocaltea at collabora.com
Thu Jul 2 07:46:13 PDT 2026
Enable HDMI 2.0 display modes (e.g. 4K at 60Hz) on the Synopsys DW HDMI QP
TX controller, as found in Rockchip RK3576 & RK3588 SoCs, by adding SCDC
management for high TMDS clock ratio and scrambling.
Since SCDC state is lost on sink disconnects, the bridge driver needs to
trigger a CRTC reset during connector detection. To support this, the
series introduces the connector and bridge scrambling infrastructure
(patches 1-8), wires it up through the bridge connector layer with an
atomic-aware detect_ctx hook (patches 9-11), then implements the SCDC
scrambling feature in the DW HDMI QP bridge driver (patches 12-15).
Patches 16-18 are minor cleanups in the Rockchip platform driver.
Patches 19-23 improve HPD handling by deferring IRQ registration until
the connector is fully initialized, adding .enable_hpd()/.disable_hpd()
PHY ops, and restricting HPD events to the affected connector.
Patches 24-25 convert vc4 HDMI to the common SCDC scrambling helpers as
a proof of reuse, replacing the driver-local scrambling implementation.
Patches 26-30 add KUnit tests: connector scrambler validation, a new
4K at 60Hz 600MHz EDID, hdmi_state_helper scrambling tests, and EDID
conformity fixes for some of the existing test blobs.
This has been tested on the following boards:
* Radxa ROCK 5B (RK3588)
* Radxa ROCK 4D (RK3576)
* Raspberry Pi 5 Model B Rev 1.1 (BCM2712 D0)
Note that commit d87773de9efe1 ("clocksource/drivers/arm_arch_timer:
Default to EL2 virtual timer when running VHE"), introduced in v7.2-rc1,
causes Raspberry Pi 5 to hang during boot. Reverting the commit
restores normal boot. This issue has already been reported in [1];
alternatively, the workaround proposed in [2] can be applied.
Regards,
Cristian
[1] https://lore.kernel.org/all/ea15cce1-b393-43f6-8d58-3d6f90f0c0cd@samsung.com/
[2] https://lore.kernel.org/all/20260619204832.586079-1-dan@reactivated.net/
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at collabora.com>
---
Changes in v8:
- Added an enum hdmi_version under video/hdmi to describe the HDMI
specification version a source/sink supports (new patch 1)
- Introduced HDMI connector capabilities API and reworked the
infrastructure patches on top of it: drmm_connector_hdmi_init() now
takes a drm_connector_hdmi_caps struct that carries supported_formats,
max_bpc, supported_hdmi_ver and max_tmds_char_rate (new patches 2-3)
- Moved all the new SCDC helpers covering both source and sink to
display/drm_hdmi_helper.c
- Renamed drm_scdc_{start,stop}_scrambling() to
drm_connector_hdmi_{enable,disable}_scrambling() and added a
connector-state argument so the scrambler_needed flag is checked
centrally instead of in every driver
- Renamed drm_scdc_sync_status() to drm_connector_hdmi_sync_scdc(),
aligned its lifecycle with vc4_hdmi_reset_link(), and removed the
internal drm_scdc_reset_crtc() helper; it now also gates on CRTC state
and an in-flight commit (Maxime)
- Changed the prototype of drm_atomic_helper_connector_hdmi_hotplug() to
take an acquire context and an int return, instead of adding a new
_ctx variant (Maxime)
- Added drm_hdmi_mode_needs_scrambling() to centralise the above-340 MHz
decision (new patch 7)
- Made SCDC source version negotiation optional and moved it to a
dedicated patch "drm/display: hdmi: Advertise SCDC source version when
scrambling" (new patch 8), backed by a new
drm_scdc_set_source_version() helper in "drm/display: scdc-helper: Add
helper to set SCDC version information" (new patch 6)
- Added a fallback TMDS rate validation patch using the connector-level
max_tmds_char_rate when the driver provides no .tmds_char_rate_valid()
hook (new patch 9)
- Split scrambler_needed flag handling into its own hdmi-state-helper
dedicate change (new patch 11)
- VC4:
* Replaced vc4_hdmi_mode_needs_scrambling() with
drm_hdmi_mode_needs_scrambling() (new patch 30)
* Restored drm_dev_{enter,exit}() pairing around the converted
scrambling paths
* Removed now unused output_{bpc,color_format} fields from vc4_hdmi as
part of the SCDC conversion
- KUnit:
* Covered the caps-based connector init path: NULL caps, inferred
max_tmds_char_rate per supported_hdmi_ver, and override validation
(new patch 32)
* Switched drm_hdmi_state_helper_test to the caps-based init helper
and exposed it through
drm_kunit_helper_connector_hdmi_init_with_caps_edid_funcs() (new
patch 34)
* Added max_tmds_char_rate fallback coverage in
drm_hdmi_state_helper_test (new patch 35)
- Rebased onto latest drm-misc-next and dropped the already applied
"drm/fb-helper: Remove unused local variable in hotplug_event()" patch
- Link to v7: https://patch.msgid.link/20260602-dw-hdmi-qp-scramb-v7-0-445eb54ee1ed@collabora.com
Changes in v7:
- Split the scrambler_needed flag computation from the SCDC scrambling
helpers into a standalone hdmi_state_helper patch for clarity (new
patch 6)
- Added vc4 HDMI conversion to common TMDS char rate constants and SCDC
scrambling helpers as a proof of reuse (new patches 24-25)
- Added KUnit tests for connector scrambler_supported/callback
consistency validation (new patch 26)
- Added 4K at 60Hz 600MHz TMDS test EDID for high-rate scrambling coverage
(new patch 27)
- Added KUnit tests for hdmi_state_helper scrambler_needed flag:
low-rate, high-rate, and source-no-support cases (new patch 28)
- Fixed EDID conformity issues (edid-decode v1.33.0 failures) in the
existing 1080p+4K YUV420 200MHz and 4K RGB/YUV 340MHz test EDIDs
without changing the capabilities used by existing tests (new patches
29-30)
- Rebased onto latest drm-misc-next
- Link to v6: https://patch.msgid.link/20260520-dw-hdmi-qp-scramb-v6-0-24b74603b782@collabora.com
Changes in v6:
- Collected R-b & A-b tags from Dmitry and Heiko
- Restructured the series from 10 into 22 patches, splitting the SCDC
scrambling helpers, connector infrastructure, bridge operations,
bridge_connector plumbing, dw-hdmi-qp implementation, and Rockchip
platform changes into distinct commits
- Added drm_scdc_dbg() macro to simplify debug messages (new patch)
- Added drm_scdc_start/stop/sync_status() helpers for full scrambling
lifecycle management (reworked from v5 patch 5)
- Added drm_atomic_helper_connector_hdmi_hotplug_ctx() to propagate
modeset acquire context for SCDC sync on hotplug (new patch)
- Added connector scrambler callbacks and SCDC work/flag infrastructure
as a separate patch (split from v5 patch 5)
- Added DRM_BRIDGE_OP_HDMI_SCRAMBLER bridge operation with
hdmi_scrambler_enable/disable callbacks (new patch)
- Implemented bridge_connector scrambler interface wiring (new patch)
- Added .enable_hpd()/.disable_hpd() PHY ops for dw-hdmi-qp bridge and
Rockchip platform drivers, replacing the obsolete .setup_hpd() op
- Added dw_hdmi_qp_hpd_notify() helper for targeted connector-only HPD
notification (split from v5 patch 10)
- Dropped drm_fb_helper_hotplug_event() unused variable (new cleanup)
- Dropped unused drm_simple_kms_helper.h include (new cleanup)
- Masked RK3576 HPD IRQ in io_init() for consistency with RK3588
- Rebased onto latest drm-misc-next
- Link to v5: https://patch.msgid.link/20260426-dw-hdmi-qp-scramb-v5-0-d778e70c317b@collabora.com
Changes in v5:
- Added new patches: 1/10, 3/10, 6/10, 7/10, 8/10
- Removed redundant no-op error check in drm_bridge_helper_reset_crtc()
(patch 1)
- Removed the EDEADLK retry loop from the bridge .detect_ctx() callback,
as that's already handled in the drm_bridge_detect_ctx() helper or by
the caller when ctx is provided (patch 2)
- Refactored drm_bridge_detect() to delegate to drm_bridge_detect_ctx()
and added a WARN_ON for unexpected negative return values (patch 2)
- Split the bridge-connector .detect_ctx() switch into a preparatory
patch to use cached connector status in .get_modes() (patch 3)
- Improved error handling in SCDC scrambling setup: roll back high TMDS
clock ratio on scrambling failure, reset scramb_enabled flag on
set_scramb failure, and add SCDC version read/write error checks
(patch 5)
- Annotated scramb_enabled with READ_ONCE/WRITE_ONCE for cross-context
access between modeset paths and the scrambling work item (patch 5)
- Renamed SCDC_MIN_SOURCE_VERSION to SCDC_MAX_SOURCE_VERSION (patch 5)
- Rate limited i2c error messages (patch 6)
- Added missing newlines in dev_err_probe() messages (patch 7)
- Replaced indirect device pointer accesses with local dev variable in
bind() (patch 8)
- Split the HPD connector restriction (formerly patch 4/4): register HPD
IRQ after connector setup first (patch 9), then restrict HPD event to
the affected connector (patch 10); also collected R-b from Heiko
- Rebased onto latest drm-misc-next
- Link to v4: https://lore.kernel.org/r/20260303-dw-hdmi-qp-scramb-v4-0-317d3b8bd219@collabora.com
Changes in v4:
- Fixed conflicts while rebasing onto latest drm-misc-next
- Link to v3: https://lore.kernel.org/r/20260119-dw-hdmi-qp-scramb-v3-0-bd8611730fc1@collabora.com
Changes in v3:
- Used drm_bridge_helper_reset_crtc() helper to reset the display
pipeline and got rid of some boilerplate code (Maxime)
- Rebased onto latest drm-misc-next
- Link to v2: https://lore.kernel.org/r/20260113-dw-hdmi-qp-scramb-v2-0-ae7b2c58d24d@collabora.com
Changes in v2:
- Collected Tested-by tags from Diederik and Maud
- Rebased onto latest drm-misc-next
- Ensured the recently introduced 'no-hpd' support for dealing with
unconnected/repurposed/broken HPD pin is limited to HDMI 1.4 rates
- Link to v1: https://lore.kernel.org/r/20251203-dw-hdmi-qp-scramb-v1-0-836fe7401a69@collabora.com
---
Cristian Ciocaltea (39):
video/hdmi: Introduce HDMI version enum
drm/connector: Add caps-based HDMI connector init helper
drm/display: bridge_connector: Pass HDMI capabilities through caps struct
drm/connector: Add HDMI 2.0 scrambler infrastructure
drm/display: scdc-helper: Add macro for connector-prefixed debug messages
drm/display: scdc-helper: Add helper to set SCDC version information
drm/display: hdmi: Add HDMI 2.0 scrambling management helpers
drm/display: hdmi: Advertise SCDC source version when scrambling
drm/display: hdmi-state-helper: Add fallback TMDS rate validation
drm/display: hdmi-state-helper: Sync SCDC state on hotplug
drm/display: hdmi-state-helper: Set HDMI scrambling requirement
drm/bridge: Remove redundant error check in drm_bridge_helper_reset_crtc()
drm/bridge: Add bridge ops for source-side HDMI 2.0 scrambling
drm/display: bridge_connector: Use cached connector status in .get_modes()
drm/display: bridge_connector: Switch to .detect_ctx() connector helper
drm/display: bridge_connector: Wire up HDMI 2.0 scrambler callbacks
drm/bridge: dw-hdmi-qp: Rate limit i2c read error messages
drm/bridge: dw-hdmi-qp: Provide .{enable|disable}_hpd() PHY ops
drm/bridge: dw-hdmi-qp: Add HDMI 2.0 SCDC scrambling support
drm/bridge: dw-hdmi-qp: Provide dw_hdmi_qp_hpd_notify() helper
drm/rockchip: dw_hdmi_qp: Add missing newlines in dev_err_probe() messages
drm/rockchip: dw_hdmi_qp: Use local dev variable consistently in bind()
drm/rockchip: dw_hdmi_qp: Drop unnecessary #include
drm/rockchip: dw_hdmi_qp: Defer HPD IRQ enable until after connector setup
drm/rockchip: dw_hdmi_qp: Mask RK3576 HPD IRQ in io_init
drm/rockchip: dw_hdmi_qp: Implement .{enable|disable}_hpd() PHY ops
drm/rockchip: dw_hdmi_qp: Use dw_hdmi_qp_hpd_notify() for HPD reports
drm/bridge: dw-hdmi-qp: Drop unused .setup_hpd() phy op
drm/vc4: hdmi: Use common TMDS char rate constants
drm/vc4: hdmi: Switch to drm_hdmi_mode_needs_scrambling()
drm/vc4: hdmi: Convert to common SCDC scrambling infrastructure
drm/tests: connector: Add HDMI caps-based init coverage
drm/tests: connector: Add HDMI source-side scrambler coverage
drm/tests: hdmi_state_helper: Use drmm_connector_hdmi_init_with_caps()
drm/tests: hdmi_state_helper: Add max_tmds_char_rate fallback tests
drm/tests: edid: Add 4K at 60Hz EDID with 600MHz TMDS
drm/tests: hdmi_state_helper: Cover source-side scrambling decision
drm/tests: edid: Fix conformity for 1080p+4K YUV420 200MHz EDID
drm/tests: edid: Fix conformity for 4K RGB/YUV 340MHz EDID
drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 129 ++++++--
drivers/gpu/drm/display/drm_bridge_connector.c | 146 +++++----
drivers/gpu/drm/display/drm_hdmi_helper.c | 267 +++++++++++++++++
drivers/gpu/drm/display/drm_hdmi_state_helper.c | 32 +-
drivers/gpu/drm/display/drm_scdc_helper.c | 70 ++++-
drivers/gpu/drm/drm_bridge_helper.c | 2 -
drivers/gpu/drm/drm_connector.c | 222 ++++++++++----
drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 130 ++++----
drivers/gpu/drm/tests/drm_connector_test.c | 330 +++++++++++++++++++++
drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 315 +++++++++++++++++++-
drivers/gpu/drm/tests/drm_kunit_edid.c | 251 +++++++++++++---
drivers/gpu/drm/tests/drm_kunit_edid.h | 1 +
drivers/gpu/drm/vc4/vc4_hdmi.c | 301 ++++---------------
drivers/gpu/drm/vc4/vc4_hdmi.h | 21 --
include/drm/bridge/dw_hdmi_qp.h | 4 +-
include/drm/display/drm_hdmi_helper.h | 15 +
include/drm/display/drm_hdmi_state_helper.h | 6 +-
include/drm/display/drm_scdc_helper.h | 2 +
include/drm/drm_bridge.h | 41 +++
include/drm/drm_connector.h | 132 +++++++++
include/linux/hdmi.h | 12 +
21 files changed, 1869 insertions(+), 560 deletions(-)
---
base-commit: 44d19b8a7548aa25cbc6ebd5f27e958f7142c36b
change-id: 20251203-dw-hdmi-qp-scramb-cdbd8b57ccf9
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