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接前一篇文章:DRM全解析 —— CRTC详解(1)
本文继续对DRM中CRTC的核心结构struct drm_crtc的成员进行释义。
3. drm_crtc结构释义
(5)struct drm_modeset_lock mutex
/*** @mutex:** This provides a read lock for the overall CRTC state (mode, dpms* state, ...) and a write lock for everything which can be update* without a full modeset (fb, cursor data, CRTC properties ...). A full* modeset also need to grab &drm_mode_config.connection_mutex.** For atomic drivers specifically this protects @state.*/struct drm_modeset_lock mutex;
此项为整个CRTC状态(mode、dpms state……)提供了读取锁,并为所有可以在没有完整modeset的情况下更新的内容(fb、cursor data、CRTC properties……)提供写入锁。完整的modeset还需要获取&drm_mode_config.connection_tmutex。
对于原子驱动程序,