[PATCH v4 0/5] drm: fix two issues related to HDMI Connector implementation

[PATCH v4 0/5] drm: fix two issues related to HDMI Connector implementation

[Dmitry Baryshkov]

Running IGT tests on Qualcomm Dragonboard820c uncovered two issues with
the HDMI Connector implementation and with its integration into the
drm_bridge_connector. Fix those issues.

Note, I'm not fully satisfied with the drm_bridge_connector move. Maybe
it's better to add drm_bridge_funcs::connector_reset() and call it from
__drm_atomic_helper_connector_reset().

Depends on https://lore.kernel.org/dri-devel/20240704-panel-sw43408-fix-v6-1-3ea1c94bbb9b@linaro.org

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
Changes in v4:
- Fixed DRM_MODE_PROP_IMMUTABLE to use MUST in the single-value clause (Maxime)
- Rebased on top of DRM_DSC_HELPERS patch
- Removed 'depends on DRM_DISPLAY_HELPER' (Maxime)
- Link to v3: https://lore.kernel.org/r/20240702-drm-bridge-connector-fix-hdmi-reset-v3-0-12b0e3124ca4@linaro.org

Changes in v3:
- Document the DRM_MODE_PROP_IMMUTABLE requirements currently exposed
  only via IGT tests (Maxime).
- Move drm_bridge_connector to drm_display_helper.
- Link to v2: https://lore.kernel.org/r/20240623-drm-bridge-connector-fix-hdmi-reset-v2-0-8590d44912ce@linaro.org

Changes in v2:
- Actually pass the flags to drm_property_create_range().
- Link to v1: https://lore.kernel.org/r/20240623-drm-bridge-connector-fix-hdmi-reset-v1-0-41e9894dcdec@linaro.org

---
Dmitry Baryshkov (5):
      drm/display: stop depending on DRM_DISPLAY_HELPER
      drm/drm_property: require DRM_MODE_PROP_IMMUTABLE for single-value props
      drm/connector: automatically set immutable flag for max_bpc property
      drm/bridge-connector: move to DRM_DISPLAY_HELPER module
      drm/bridge-connector: reset the HDMI connector state

 MAINTAINERS                                        |  2 +-
 drivers/gpu/drm/Makefile                           |  1 -
 drivers/gpu/drm/bridge/Kconfig                     |  1 +
 drivers/gpu/drm/display/Kconfig                    | 25 ++++++++++++----------
 drivers/gpu/drm/display/Makefile                   |  2 ++
 .../gpu/drm/{ => display}/drm_bridge_connector.c   | 13 ++++++++++-
 drivers/gpu/drm/drm_connector.c                    |  7 +++++-
 drivers/gpu/drm/imx/dcss/Kconfig                   |  2 ++
 drivers/gpu/drm/imx/lcdc/Kconfig                   |  2 ++
 drivers/gpu/drm/ingenic/Kconfig                    |  2 ++
 drivers/gpu/drm/kmb/Kconfig                        |  2 ++
 drivers/gpu/drm/mediatek/Kconfig                   |  2 ++
 drivers/gpu/drm/meson/Kconfig                      |  2 ++
 drivers/gpu/drm/msm/Kconfig                        |  1 +
 drivers/gpu/drm/omapdrm/Kconfig                    |  2 ++
 drivers/gpu/drm/renesas/rcar-du/Kconfig            |  2 ++
 drivers/gpu/drm/renesas/rz-du/Kconfig              |  2 ++
 drivers/gpu/drm/renesas/shmobile/Kconfig           |  2 ++
 drivers/gpu/drm/rockchip/Kconfig                   |  4 ++++
 drivers/gpu/drm/tegra/Kconfig                      |  1 +
 drivers/gpu/drm/tidss/Kconfig                      |  2 ++
 drivers/gpu/drm/xlnx/Kconfig                       |  1 +
 include/drm/drm_property.h                         |  3 +++
 23 files changed, 68 insertions(+), 15 deletions(-)
---
base-commit: cfbc154f11aaa32b4b2887323e4372390648046d
change-id: 20240623-drm-bridge-connector-fix-hdmi-reset-0ce86af053aa

Best regards,
-- 
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

[PATCH v4 1/5] drm/display: stop depending on DRM_DISPLAY_HELPER

[Dmitry Baryshkov]

Kconfig symbols should not declare dependency on DRM_DISPLAY_HELPER.
Move all parts of DRM_DISPLAY_HELPER to an if DRM_DISPLAY_HELPER block.

It is not possible to make those symbols select DRM_DISPLAY_HELPER
because of the link issues when a part of the helper is selected to be
built-in, while other part is selected to be as module. In such a case
the modular part doesn't get built at all, leading to undefined symbols.

The only viable alternative is to split drm_display_helper.ko into
several small modules, each of them having their own dependencies.

Suggested-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/display/Kconfig | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig
index a2e42014ffe0..9c2da1e48b75 100644
--- a/drivers/gpu/drm/display/Kconfig
+++ b/drivers/gpu/drm/display/Kconfig
@@ -1,19 +1,20 @@
 # SPDX-License-Identifier: MIT
 
+config DRM_DISPLAY_DP_AUX_BUS
+	tristate
+	depends on DRM
+	depends on OF || COMPILE_TEST
+
 config DRM_DISPLAY_HELPER
 	tristate
 	depends on DRM
 	help
 	  DRM helpers for display adapters.
 
-config DRM_DISPLAY_DP_AUX_BUS
-	tristate
-	depends on DRM
-	depends on OF || COMPILE_TEST
+if DRM_DISPLAY_HELPER
 
 config DRM_DISPLAY_DP_AUX_CEC
 	bool "Enable DisplayPort CEC-Tunneling-over-AUX HDMI support"
-	depends on DRM && DRM_DISPLAY_HELPER
 	select DRM_DISPLAY_DP_HELPER
 	select CEC_CORE
 	help
@@ -25,7 +26,6 @@ config DRM_DISPLAY_DP_AUX_CEC
 
 config DRM_DISPLAY_DP_AUX_CHARDEV
 	bool "DRM DP AUX Interface"
-	depends on DRM && DRM_DISPLAY_HELPER
 	select DRM_DISPLAY_DP_HELPER
 	help
 	  Choose this option to enable a /dev/drm_dp_auxN node that allows to
@@ -34,7 +34,6 @@ config DRM_DISPLAY_DP_AUX_CHARDEV
 
 config DRM_DISPLAY_DP_HELPER
 	bool
-	depends on DRM_DISPLAY_HELPER
 	help
 	  DRM display helpers for DisplayPort.
 
@@ -61,25 +60,23 @@ config DRM_DISPLAY_DP_TUNNEL_STATE_DEBUG
 
 config DRM_DISPLAY_DSC_HELPER
 	bool
-	depends on DRM_DISPLAY_HELPER
 	help
 	  DRM display helpers for VESA DSC (used by DSI and DisplayPort).
 
 config DRM_DISPLAY_HDCP_HELPER
 	bool
-	depends on DRM_DISPLAY_HELPER
 	help
 	  DRM display helpers for HDCP.
 
 config DRM_DISPLAY_HDMI_HELPER
 	bool
-	depends on DRM_DISPLAY_HELPER
 	help
 	  DRM display helpers for HDMI.
 
 config DRM_DISPLAY_HDMI_STATE_HELPER
 	bool
-	depends on DRM_DISPLAY_HELPER
 	select DRM_DISPLAY_HDMI_HELPER
 	help
 	  DRM KMS state helpers for HDMI.
+
+endif # DRM_DISPLAY_HELPER

-- 
2.39.2

[PATCH v4 2/5] drm/drm_property: require DRM_MODE_PROP_IMMUTABLE for single-value props

[Dmitry Baryshkov]

Document that DRM_MODE_PROP_IMMUTABLE must be set for the properties
that are immutable by definition - e.g. ranges with min == max or enums
with a single value. This matches the behaviour of the IGT tests, see
kms_properties.c / validate_range_prop(), validate_enum_prop(),
validate_bitmask_prop().

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 include/drm/drm_property.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/drm/drm_property.h b/include/drm/drm_property.h
index 082f29156b3e..d78ec42de42f 100644
--- a/include/drm/drm_property.h
+++ b/include/drm/drm_property.h
@@ -162,6 +162,9 @@ struct drm_property {
 	 *     userspace, e.g. the EDID, or the connector path property on DP
 	 *     MST sinks. Kernel can update the value of an immutable property
 	 *     by calling drm_object_property_set_value().
+	 *     This flag MUST be set for all properties that have only a
+	 *     single value (e.g. min == max or if enum has only a single
+	 *     value).
 	 */
 	uint32_t flags;
 

-- 
2.39.2

[PATCH v4 3/5] drm/connector: automatically set immutable flag for max_bpc property

[Dmitry Baryshkov]

With the introduction of the HDMI Connector framework the driver might
end up creating the max_bpc property with min = max = 8. IGT insists
that such properties carry the 'immutable' flag. Automatically set the
flag if the driver asks for the max_bpc property with min == max.

Fixes: aadb3e16b8f3 ("drm/connector: hdmi: Add output BPC to the connector state")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/drm_connector.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index ab6ab7ff7ea8..33847fd63628 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2610,7 +2610,12 @@ int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
 
 	prop = connector->max_bpc_property;
 	if (!prop) {
-		prop = drm_property_create_range(dev, 0, "max bpc", min, max);
+		u32 flags = 0;
+
+		if (min == max)
+			flags |= DRM_MODE_PROP_IMMUTABLE;
+
+		prop = drm_property_create_range(dev, flags, "max bpc", min, max);
 		if (!prop)
 			return -ENOMEM;
 

-- 
2.39.2

[PATCH v4 4/5] drm/bridge-connector: move to DRM_DISPLAY_HELPER module

[Dmitry Baryshkov]

drm_bridge_connector is a "leaf" driver, belonging to the display
helper, rather than the "CRTC" drm_kms_helper module. Move the driver
to the drm/display and add necessary Kconfig selection clauses.

Suggested-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 MAINTAINERS                                          | 2 +-
 drivers/gpu/drm/Makefile                             | 1 -
 drivers/gpu/drm/bridge/Kconfig                       | 1 +
 drivers/gpu/drm/display/Kconfig                      | 5 +++++
 drivers/gpu/drm/display/Makefile                     | 2 ++
 drivers/gpu/drm/{ => display}/drm_bridge_connector.c | 0
 drivers/gpu/drm/imx/dcss/Kconfig                     | 2 ++
 drivers/gpu/drm/imx/lcdc/Kconfig                     | 2 ++
 drivers/gpu/drm/ingenic/Kconfig                      | 2 ++
 drivers/gpu/drm/kmb/Kconfig                          | 2 ++
 drivers/gpu/drm/mediatek/Kconfig                     | 2 ++
 drivers/gpu/drm/meson/Kconfig                        | 2 ++
 drivers/gpu/drm/msm/Kconfig                          | 1 +
 drivers/gpu/drm/omapdrm/Kconfig                      | 2 ++
 drivers/gpu/drm/renesas/rcar-du/Kconfig              | 2 ++
 drivers/gpu/drm/renesas/rz-du/Kconfig                | 2 ++
 drivers/gpu/drm/renesas/shmobile/Kconfig             | 2 ++
 drivers/gpu/drm/rockchip/Kconfig                     | 4 ++++
 drivers/gpu/drm/tegra/Kconfig                        | 1 +
 drivers/gpu/drm/tidss/Kconfig                        | 2 ++
 drivers/gpu/drm/xlnx/Kconfig                         | 1 +
 21 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index fb1df8c29f5a..5b5520ed57fe 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7463,8 +7463,8 @@ S:	Maintained
 T:	git https://gitlab.freedesktop.org/drm/misc/kernel.git
 F:	Documentation/devicetree/bindings/display/bridge/
 F:	drivers/gpu/drm/bridge/
+F:	drivers/gpu/drm/display/drm_bridge_connector.c
 F:	drivers/gpu/drm/drm_bridge.c
-F:	drivers/gpu/drm/drm_bridge_connector.c
 F:	include/drm/drm_bridge.h
 F:	include/drm/drm_bridge_connector.h
 
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 68cc9258ffc4..fa432a1ac9e2 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -128,7 +128,6 @@ obj-$(CONFIG_DRM_TTM_HELPER) += drm_ttm_helper.o
 drm_kms_helper-y := \
 	drm_atomic_helper.o \
 	drm_atomic_state_helper.o \
-	drm_bridge_connector.o \
 	drm_crtc_helper.o \
 	drm_damage_helper.o \
 	drm_encoder_slave.o \
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index c621be1a99a8..3eb955333c80 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -390,6 +390,7 @@ config DRM_TI_SN65DSI86
 	depends on OF
 	select DRM_DISPLAY_DP_HELPER
 	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_KMS_HELPER
 	select REGMAP_I2C
 	select DRM_PANEL
diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig
index 9c2da1e48b75..8c174ceb0c4d 100644
--- a/drivers/gpu/drm/display/Kconfig
+++ b/drivers/gpu/drm/display/Kconfig
@@ -13,6 +13,11 @@ config DRM_DISPLAY_HELPER
 
 if DRM_DISPLAY_HELPER
 
+config DRM_BRIDGE_CONNECTOR
+	bool
+	help
+	  DRM connector implementation terminating DRM bridge chains.
+
 config DRM_DISPLAY_DP_AUX_CEC
 	bool "Enable DisplayPort CEC-Tunneling-over-AUX HDMI support"
 	select DRM_DISPLAY_DP_HELPER
diff --git a/drivers/gpu/drm/display/Makefile b/drivers/gpu/drm/display/Makefile
index a023f72fa139..629c834c3192 100644
--- a/drivers/gpu/drm/display/Makefile
+++ b/drivers/gpu/drm/display/Makefile
@@ -3,6 +3,8 @@
 obj-$(CONFIG_DRM_DISPLAY_DP_AUX_BUS) += drm_dp_aux_bus.o
 
 drm_display_helper-y := drm_display_helper_mod.o
+drm_display_helper-$(CONFIG_DRM_BRIDGE_CONNECTOR) += \
+	drm_bridge_connector.o
 drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_HELPER) += \
 	drm_dp_dual_mode_helper.o \
 	drm_dp_helper.o \
diff --git a/drivers/gpu/drm/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
similarity index 100%
rename from drivers/gpu/drm/drm_bridge_connector.c
rename to drivers/gpu/drm/display/drm_bridge_connector.c
diff --git a/drivers/gpu/drm/imx/dcss/Kconfig b/drivers/gpu/drm/imx/dcss/Kconfig
index 3ffc061d392b..59e3b6a1dff0 100644
--- a/drivers/gpu/drm/imx/dcss/Kconfig
+++ b/drivers/gpu/drm/imx/dcss/Kconfig
@@ -2,6 +2,8 @@ config DRM_IMX_DCSS
 	tristate "i.MX8MQ DCSS"
 	select IMX_IRQSTEER
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
 	select VIDEOMODE_HELPERS
 	depends on DRM && ARCH_MXC && ARM64
diff --git a/drivers/gpu/drm/imx/lcdc/Kconfig b/drivers/gpu/drm/imx/lcdc/Kconfig
index 7e57922bbd9d..9c28bb0f4662 100644
--- a/drivers/gpu/drm/imx/lcdc/Kconfig
+++ b/drivers/gpu/drm/imx/lcdc/Kconfig
@@ -3,5 +3,7 @@ config DRM_IMX_LCDC
       depends on DRM && (ARCH_MXC || COMPILE_TEST)
       select DRM_GEM_DMA_HELPER
       select DRM_KMS_HELPER
+      select DRM_DISPLAY_HELPER
+      select DRM_BRIDGE_CONNECTOR
       help
         Found on i.MX1, i.MX21, i.MX25 and i.MX27.
diff --git a/drivers/gpu/drm/ingenic/Kconfig b/drivers/gpu/drm/ingenic/Kconfig
index 3db117c5edd9..8cd7b750dffe 100644
--- a/drivers/gpu/drm/ingenic/Kconfig
+++ b/drivers/gpu/drm/ingenic/Kconfig
@@ -8,6 +8,8 @@ config DRM_INGENIC
 	select DRM_BRIDGE
 	select DRM_PANEL_BRIDGE
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
 	select REGMAP
 	select REGMAP_MMIO
diff --git a/drivers/gpu/drm/kmb/Kconfig b/drivers/gpu/drm/kmb/Kconfig
index fd011367db1d..e5ae3ec52392 100644
--- a/drivers/gpu/drm/kmb/Kconfig
+++ b/drivers/gpu/drm/kmb/Kconfig
@@ -3,6 +3,8 @@ config DRM_KMB_DISPLAY
 	depends on DRM
 	depends on ARCH_KEEMBAY || COMPILE_TEST
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
 	select DRM_MIPI_DSI
 	help
diff --git a/drivers/gpu/drm/mediatek/Kconfig b/drivers/gpu/drm/mediatek/Kconfig
index d6449ebae838..417ac8c9af41 100644
--- a/drivers/gpu/drm/mediatek/Kconfig
+++ b/drivers/gpu/drm/mediatek/Kconfig
@@ -9,6 +9,8 @@ config DRM_MEDIATEK
 	depends on MTK_MMSYS
 	select DRM_GEM_DMA_HELPER if DRM_FBDEV_EMULATION
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_MIPI_DSI
 	select DRM_PANEL
 	select MEMORY
diff --git a/drivers/gpu/drm/meson/Kconfig b/drivers/gpu/drm/meson/Kconfig
index 615fdd0ce41b..2544756538cc 100644
--- a/drivers/gpu/drm/meson/Kconfig
+++ b/drivers/gpu/drm/meson/Kconfig
@@ -4,6 +4,8 @@ config DRM_MESON
 	depends on DRM && OF && (ARM || ARM64)
 	depends on ARCH_MESON || COMPILE_TEST
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
 	select DRM_DISPLAY_CONNECTOR
 	select VIDEOMODE_HELPERS
diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
index 420385c47193..94d3ed4f7761 100644
--- a/drivers/gpu/drm/msm/Kconfig
+++ b/drivers/gpu/drm/msm/Kconfig
@@ -17,6 +17,7 @@ config DRM_MSM
 	select DRM_DISPLAY_DP_AUX_BUS
 	select DRM_DISPLAY_DP_HELPER
 	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_EXEC
 	select DRM_KMS_HELPER
 	select DRM_PANEL
diff --git a/drivers/gpu/drm/omapdrm/Kconfig b/drivers/gpu/drm/omapdrm/Kconfig
index 6c49270cb290..0c6d5afc1ef4 100644
--- a/drivers/gpu/drm/omapdrm/Kconfig
+++ b/drivers/gpu/drm/omapdrm/Kconfig
@@ -4,6 +4,8 @@ config DRM_OMAP
 	depends on DRM && OF
 	depends on ARCH_OMAP2PLUS
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select FB_DMAMEM_HELPERS_DEFERRED if DRM_FBDEV_EMULATION
 	select VIDEOMODE_HELPERS
 	select HDMI
diff --git a/drivers/gpu/drm/renesas/rcar-du/Kconfig b/drivers/gpu/drm/renesas/rcar-du/Kconfig
index c17e7c50492c..025677fe88d3 100644
--- a/drivers/gpu/drm/renesas/rcar-du/Kconfig
+++ b/drivers/gpu/drm/renesas/rcar-du/Kconfig
@@ -5,6 +5,8 @@ config DRM_RCAR_DU
 	depends on ARM || ARM64 || COMPILE_TEST
 	depends on ARCH_RENESAS || COMPILE_TEST
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
 	select VIDEOMODE_HELPERS
 	help
diff --git a/drivers/gpu/drm/renesas/rz-du/Kconfig b/drivers/gpu/drm/renesas/rz-du/Kconfig
index 5f0db2c5fee6..e1a6dd322caf 100644
--- a/drivers/gpu/drm/renesas/rz-du/Kconfig
+++ b/drivers/gpu/drm/renesas/rz-du/Kconfig
@@ -6,6 +6,8 @@ config DRM_RZG2L_DU
 	depends on VIDEO_RENESAS_VSP1
 	select DRM_GEM_DMA_HELPER
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select VIDEOMODE_HELPERS
 	help
 	  Choose this option if you have an RZ/G2L alike chipset.
diff --git a/drivers/gpu/drm/renesas/shmobile/Kconfig b/drivers/gpu/drm/renesas/shmobile/Kconfig
index 027220b8fe1c..c329ab8a7a8b 100644
--- a/drivers/gpu/drm/renesas/shmobile/Kconfig
+++ b/drivers/gpu/drm/renesas/shmobile/Kconfig
@@ -5,6 +5,8 @@ config DRM_SHMOBILE
 	depends on ARCH_RENESAS || ARCH_SHMOBILE || COMPILE_TEST
 	select BACKLIGHT_CLASS_DEVICE
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
 	select VIDEOMODE_HELPERS
 	help
diff --git a/drivers/gpu/drm/rockchip/Kconfig b/drivers/gpu/drm/rockchip/Kconfig
index 7df875e38517..23c49e91f1cc 100644
--- a/drivers/gpu/drm/rockchip/Kconfig
+++ b/drivers/gpu/drm/rockchip/Kconfig
@@ -86,6 +86,8 @@ config ROCKCHIP_LVDS
 	bool "Rockchip LVDS support"
 	depends on DRM_ROCKCHIP
 	depends on PINCTRL && OF
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	help
 	  Choose this option to enable support for Rockchip LVDS controllers.
 	  Rockchip rk3288 SoC has LVDS TX Controller can be used, and it
@@ -96,6 +98,8 @@ config ROCKCHIP_RGB
 	bool "Rockchip RGB support"
 	depends on DRM_ROCKCHIP
 	depends on PINCTRL
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	help
 	  Choose this option to enable support for Rockchip RGB output.
 	  Some Rockchip CRTCs, like rv1108, can directly output parallel
diff --git a/drivers/gpu/drm/tegra/Kconfig b/drivers/gpu/drm/tegra/Kconfig
index 782f51d3044a..e688d8104652 100644
--- a/drivers/gpu/drm/tegra/Kconfig
+++ b/drivers/gpu/drm/tegra/Kconfig
@@ -8,6 +8,7 @@ config DRM_TEGRA
 	select DRM_DISPLAY_DP_HELPER
 	select DRM_DISPLAY_HDMI_HELPER
 	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_DISPLAY_DP_AUX_BUS
 	select DRM_KMS_HELPER
 	select DRM_MIPI_DSI
diff --git a/drivers/gpu/drm/tidss/Kconfig b/drivers/gpu/drm/tidss/Kconfig
index 378600806167..2385c56493b9 100644
--- a/drivers/gpu/drm/tidss/Kconfig
+++ b/drivers/gpu/drm/tidss/Kconfig
@@ -3,6 +3,8 @@ config DRM_TIDSS
 	depends on DRM && OF
 	depends on ARM || ARM64 || COMPILE_TEST
 	select DRM_KMS_HELPER
+	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
 	help
 	  The TI Keystone family SoCs introduced a new generation of
diff --git a/drivers/gpu/drm/xlnx/Kconfig b/drivers/gpu/drm/xlnx/Kconfig
index 68ee897de9d7..626e5ac4c33d 100644
--- a/drivers/gpu/drm/xlnx/Kconfig
+++ b/drivers/gpu/drm/xlnx/Kconfig
@@ -8,6 +8,7 @@ config DRM_ZYNQMP_DPSUB
 	select DMA_ENGINE
 	select DRM_DISPLAY_DP_HELPER
 	select DRM_DISPLAY_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
 	select DRM_KMS_HELPER
 	select GENERIC_PHY

-- 
2.39.2

[PATCH v4 5/5] drm/bridge-connector: reset the HDMI connector state

[Dmitry Baryshkov]

On HDMI connectors which use drm_bridge_connector and DRM_BRIDGE_OP_HDMI
IGT chokes on the max_bpc property in several kms_properties tests due
to the drm_bridge_connector failing to reset HDMI-related
properties.

Call __drm_atomic_helper_connector_hdmi_reset() if the
drm_bridge_connector has bridge_hdmi.

It is impossible to call this function from HDMI bridges, none of the
bridge callbacks correspond to the drm_connector_funcs::reset().

Fixes: 6b4468b0c6ba ("drm/bridge-connector: implement glue code for HDMI connector")
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/display/Kconfig                |  1 +
 drivers/gpu/drm/display/drm_bridge_connector.c | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig
index 8c174ceb0c4d..3763649ba251 100644
--- a/drivers/gpu/drm/display/Kconfig
+++ b/drivers/gpu/drm/display/Kconfig
@@ -15,6 +15,7 @@ if DRM_DISPLAY_HELPER
 
 config DRM_BRIDGE_CONNECTOR
 	bool
+	select DRM_DISPLAY_HDMI_STATE_HELPER
 	help
 	  DRM connector implementation terminating DRM bridge chains.
 
diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 0869b663f17e..7ebb35438459 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -216,8 +216,19 @@ static void drm_bridge_connector_debugfs_init(struct drm_connector *connector,
 	}
 }
 
+static void drm_bridge_connector_reset(struct drm_connector *connector)
+{
+	struct drm_bridge_connector *bridge_connector =
+		to_drm_bridge_connector(connector);
+
+	drm_atomic_helper_connector_reset(connector);
+	if (bridge_connector->bridge_hdmi)
+		__drm_atomic_helper_connector_hdmi_reset(connector,
+							 connector->state);
+}
+
 static const struct drm_connector_funcs drm_bridge_connector_funcs = {
-	.reset = drm_atomic_helper_connector_reset,
+	.reset = drm_bridge_connector_reset,
 	.detect = drm_bridge_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,

-- 
2.39.2

Re: [PATCH v4 5/5] drm/bridge-connector: reset the HDMI connector state

[Maxime Ripard]

On Mon, 15 Jul 2024 09:33:05 +0300, Dmitry Baryshkov wrote:
> On HDMI connectors which use drm_bridge_connector and DRM_BRIDGE_OP_HDMI
> IGT chokes on the max_bpc property in several kms_properties tests due
> to the drm_bridge_connector failing to reset HDMI-related
> properties.
> 
> 
> [ ... ]

Acked-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH v4 4/5] drm/bridge-connector: move to DRM_DISPLAY_HELPER module

[Maxime Ripard]

On Mon, 15 Jul 2024 09:33:04 +0300, Dmitry Baryshkov wrote:
> drm_bridge_connector is a "leaf" driver, belonging to the display
> helper, rather than the "CRTC" drm_kms_helper module. Move the driver
> to the drm/display and add necessary Kconfig selection clauses.
> 
> Suggested-by: Maxime Ripard <mripard@kernel.org>
> 
> [ ... ]

Acked-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH v4 3/5] drm/connector: automatically set immutable flag for max_bpc property

[Maxime Ripard]

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On Mon, Jul 15, 2024 at 09:33:03AM GMT, Dmitry Baryshkov wrote:
> With the introduction of the HDMI Connector framework the driver might
> end up creating the max_bpc property with min = max = 8. IGT insists
> that such properties carry the 'immutable' flag. Automatically set the
> flag if the driver asks for the max_bpc property with min == max.
> 
> Fixes: aadb3e16b8f3 ("drm/connector: hdmi: Add output BPC to the connector state")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Assuming that someone on the uapi sides agrees to patch 3:

Acked-by: Maxime Ripard <mripard@kernel.org>

Maxime

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Re: [PATCH v4 2/5] drm/drm_property: require DRM_MODE_PROP_IMMUTABLE for single-value props

[Maxime Ripard]

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Hi,

On Mon, Jul 15, 2024 at 09:33:02AM GMT, Dmitry Baryshkov wrote:
> Document that DRM_MODE_PROP_IMMUTABLE must be set for the properties
> that are immutable by definition - e.g. ranges with min == max or enums
> with a single value. This matches the behaviour of the IGT tests, see
> kms_properties.c / validate_range_prop(), validate_enum_prop(),
> validate_bitmask_prop().
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

We had a discussion yesterday about it on IRC with Sima, Simon and
Xaver.

https://oftc.irclog.whitequark.org/dri-devel/2024-07-16#33374622;

The conclusion was that it would create an inconsistency between drivers
on whether a given property is immutable or not, which will lead to more
troubles for userspace.

It's not clear why Ville added that check in the first place, so the
best course of action is to remove the IGT test and get the discussion
started there.

Maxime

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Re: [PATCH v4 2/5] drm/drm_property: require DRM_MODE_PROP_IMMUTABLE for single-value props

[Dmitry Baryshkov]

On Wed, Jul 17, 2024 at 03:42:46PM GMT, Maxime Ripard wrote:
> Hi,
> 
> On Mon, Jul 15, 2024 at 09:33:02AM GMT, Dmitry Baryshkov wrote:
> > Document that DRM_MODE_PROP_IMMUTABLE must be set for the properties
> > that are immutable by definition - e.g. ranges with min == max or enums
> > with a single value. This matches the behaviour of the IGT tests, see
> > kms_properties.c / validate_range_prop(), validate_enum_prop(),
> > validate_bitmask_prop().
> > 
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> 
> We had a discussion yesterday about it on IRC with Sima, Simon and
> Xaver.
> 
> https://oftc.irclog.whitequark.org/dri-devel/2024-07-16#33374622;
> 
> The conclusion was that it would create an inconsistency between drivers
> on whether a given property is immutable or not, which will lead to more
> troubles for userspace.
> 
> It's not clear why Ville added that check in the first place, so the
> best course of action is to remove the IGT test and get the discussion
> started there.

Ack, I'll work on removing those tests later today.

-- 
With best wishes
Dmitry