Re: [PATCH v4 00/13] Apply drm_bridge_connector and panel_bridge helper for the Analogix DP driver

[Marek Szyprowski <m.szyprowski@samsung.com>]

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
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland