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 > ... Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
