On 01.09.2025 05:41, Damon Ding wrote: > On 8/29/2025 4:23 PM, Marek Szyprowski wrote: >> On 29.08.2025 10:08, Damon Ding wrote: >>> On 8/20/2025 5:20 AM, Marek Szyprowski wrote: >>>> On 15.08.2025 04:59, Damon Ding wrote: >>>>> On 2025/8/15 5:16, Marek Szyprowski wrote: >>>>>> On 14.08.2025 16:33, Marek Szyprowski wrote: >>>>>>> On 14.08.2025 12:47, Damon Ding wrote: >>>>>>>> PATCH 1 is a small format optimization for struct >>>>>>>> analogid_dp_device. >>>>>>>> PATCH 2 is to perform mode setting in >>>>>>>> &drm_bridge_funcs.atomic_enable. >>>>>>>> PATCH 3-6 are preparations for apply drm_bridge_connector helper. >>>>>>>> PATCH 7 is to apply the drm_bridge_connector helper. >>>>>>>> PATCH 8-10 are to move the panel/bridge parsing to the Analogix >>>>>>>> side. >>>>>>>> PATCH 11-12 are preparations for apply panel_bridge helper. >>>>>>>> PATCH 13 is to apply the panel_bridge helper. >>>>>>> >>>>>>> This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's >>>>>>> Kconfig, >>>>>>> so it causes build break: >>>>>>> >>>>>>> drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to >>>>>>> `drm_bridge_connector_init' >>>>>>> make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1 >>>>>>> >>>>>>> After adding this dependency, the Exynos DP driver stops >>>>>>> working. On >>>>>>> Samsung Snow Chromebook I observed following issue: >>>>>>> >>>>>>> [ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach >>>>>>> following panel or bridge (-16) >>>>>>> [ 4.543428] exynos-drm exynos-drm: failed to bind >>>>>>> 145b0000.dp-controller (ops exynos_dp_ops): -16 >>>>>>> [ 4.551775] exynos-drm exynos-drm: adev bind failed: -16 >>>>>>> [ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver >>>>>>> exynos-dp failed with error -16 >>>>>>> >>>>>>> I will investigate details later in the evening. >>>>>> >>>>>> The failure is caused by trying to add plat_data->next_bridge twice >>>>>> (from exynos_dp's .attach callback, and from analogix' ->bind >>>>>> callback). >>>>>> >>>>>> >>>>>> Best regards >>>>> >>>>> I see. The bridge attachment for the next bridge was not well thought >>>>> out. It may be better to move panel_bridge addition a little forward >>>>> and remove next_bridge attachment on the Analogix side. Then, the >>>>> Rockchip side and Exynos side can do their own next_bridge attachment >>>>> in &analogix_dp_plat_data.attach() as they want. >>>>> >>>>> Could you please help test the following modifications(they have been >>>>> tested on my RK3588S EVB1 Board) on the Samsung Snow Chromebook? ;-) >>>> >>>> Assuming that I properly applied the malformed diff, it doesn't solve >>>> all the issues. There are no errors reported though, but the display >>>> chain doesn't work and no valid mode is reported: >>>> >>>> # dmesg | grep drm >>>> [ 3.384992] [drm] Initialized panfrost 1.4.0 for 11800000.gpu on >>>> minor 0 >>>> [ 4.487739] [drm] Exynos DRM: using 14400000.fimd device for DMA >>>> mapping operations >>>> [ 4.494202] exynos-drm exynos-drm: bound 14400000.fimd (ops >>>> fimd_component_ops) >>>> [ 4.502374] exynos-drm exynos-drm: bound 14450000.mixer (ops >>>> mixer_component_ops) >>>> [ 4.511930] exynos-drm exynos-drm: bound 145b0000.dp-controller >>>> (ops >>>> exynos_dp_ops) >>>> [ 4.518411] exynos-drm exynos-drm: bound 14530000.hdmi (ops >>>> hdmi_component_ops) >>>> [ 4.529628] [drm] Initialized exynos 1.1.0 for exynos-drm on >>>> minor 1 >>>> [ 4.657434] exynos-drm exynos-drm: [drm] Cannot find any crtc or >>>> sizes >>>> [ 4.925023] exynos-drm exynos-drm: [drm] Cannot find any crtc or >>>> sizes >>>> >>>> # ./modetest -c -Mexynos >>>> Connectors: >>>> id encoder status name size (mm) modes >>>> encoders >>>> 69 0 disconnected LVDS-1 0x0 0 >>>> 68 >>>> props: >>>> 1 EDID: >>>> flags: immutable blob >>>> blobs: >>>> >>>> value: >>>> 2 DPMS: >>>> flags: enum >>>> enums: On=0 Standby=1 Suspend=2 Off=3 >>>> value: 0 >>>> 5 link-status: >>>> flags: enum >>>> enums: Good=0 Bad=1 >>>> value: 0 >>>> 6 non-desktop: >>>> flags: immutable range >>>> values: 0 1 >>>> value: 0 >>>> 4 TILE: >>>> flags: immutable blob >>>> blobs: >>>> >>>> value: >>>> 71 0 disconnected HDMI-A-1 0x0 0 >>>> 70 >>>> props: >>>> 1 EDID: >>>> flags: immutable blob >>>> blobs: >>>> >>>> value: >>>> 2 DPMS: >>>> flags: enum >>>> enums: On=0 Standby=1 Suspend=2 Off=3 >>>> value: 0 >>>> 5 link-status: >>>> flags: enum >>>> enums: Good=0 Bad=1 >>>> value: 0 >>>> 6 non-desktop: >>>> flags: immutable range >>>> values: 0 1 >>>> value: 0 >>>> 4 TILE: >>>> flags: immutable blob >>>> blobs: >>>> >>>> value: >>>> >>>> >>>> I will investigate details later this week. >>>> >>> >>> Could you please provide the related DTS file for the test? I will >>> also try to find out the reason for this unexpected issue. ;-) >> >> Unfortunately I didn't find enough time to debug this further. The above >> log is from Samsung Snow Chromebook, >> arch/arm/boot/dts/samsung/exynos5250-snow.dts >> >> > > I compare the differences in the following display path before and > after this patch series: > > exynos_dp -> nxp-ptn3460 -> panel "auo,b116xw03" > > The issue is likely caused by the &drm_connector_funcs.detect() > related logic. Before this patch series, the nxp-ptn3460 connector is > always connector_status_connected because there is not available > &drm_connector_funcs.detect(). After it, the DRM_BRIDGE_OP_DETECT flag > make the connection status depend on analogix_dp_bridge_detect(). > > Could you please add the following patches additionally and try again? > (Not the final solution, just validation) > > diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > index a93ff8f0a468..355911c47354 100644 > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > @@ -1491,9 +1491,11 @@ int analogix_dp_bind(struct analogix_dp_device > *dp, struct drm_device *drm_dev) > } > } > > - bridge->ops = DRM_BRIDGE_OP_DETECT | > - DRM_BRIDGE_OP_EDID | > + bridge->ops = DRM_BRIDGE_OP_EDID | > DRM_BRIDGE_OP_MODES; > + if (drm_bridge_is_panel(dp->plat_data->next_bridge)) > + bridge->ops |= DRM_BRIDGE_OP_DETECT; > + > bridge->of_node = dp->dev->of_node; > bridge->type = DRM_MODE_CONNECTOR_eDP; > ret = devm_drm_bridge_add(dp->dev, &dp->bridge);
It is better. Now the display panel is detected and reported to userspace, but it looks that something is not properly initialized, because there is garbage instead of the proper picture. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
