1053429657#Note-xiaoshujiang#[Linux4.4][RK3399] DRM HDMI 调试小结1

--- title: [Linux][RK3399] HDMI 调试小结 tags: hdmi,rockchip grammar_cjkRuby: true --- Platform: RK3399 OS: Android 6.0 Kernel: 4.4 Version: v2017.04 ## 调试流程 ### 确认板子是否识别到了显示器的 EDID ``` echo 0x1f > /sys/module/drm/parameters/debug ``` 插拔一下hdmi 然后dmesg | grep drm, 看看里面的信息是否解析到了edid ``` [ 405.576876] EDID block is all zeroes [ 405.577224] rockchip-drm display-subsystem: HDMI-A-1: EDID block 0 invalid. [ 405.687232] EDID block is all zeroes [ 405.687590] rockchip-drm display-subsystem: HDMI-A-1: EDID block 0 invalid. ``` EDID = 0 这个就是显示器被识别为DVI的主因, 当无法读出edid时, hdmi驱动可能就会以dvi显示输出 ### 测一下hdmi驱动是否可以支持hdmi输出 使能 CONFIG_DRM_LOAD_EDID_FIRMWARE （参考 https://markyzq.gitbooks.io/rockchip_drm_integration_helper/content/zh/drm_config_load_firmware.html