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由 Haneen Mohammed 提交于
This patch implement the necessary functions to compute and add CRCs entries: - Implement the set_crc_source() callback. - Compute CRC using crc32 on the visible part of the framebuffer. - Use ordered workqueue per output to compute and add CRC at the end of a vblank. - Use appropriate synchronization methods since the CRC computation must be atomic wrt the generated vblank event for a given atomic update, by using spinlock across atomic_begin/atomic_flush to wrap the event handling code completely and match the flip event with the CRC. Since vkms_crc_work_handle() can sleep, spinlock can't be acquired while accessing vkms_output->primary_crc to compute CRC. To make sure the data is updated and released without conflict with the vkms_crc_work_handle(), the work_struct is flushed @crtc_destroy and the data is updated before scheduling the work handle again, as follow: * CRC data update: 1- store vkms_crc_data {fb, src} per plane_state 2- @plane_duplicate_state -> allocate vkms_crc_data 3- during atomic commit (@atomic_update) -> a) copy {fb, src} to plane_state->crc_data b) get reference to fb, 3- @plane_destroy_state -> a) if (fb refcount) remove reference to fb b) deallocate crc_data * Atomic Commit: 1- vkms_plane_atomic_check 2- vkms_prepare_fb -> vmap vkms_gem_obj->vaddr 3- atomic_begin -> hold crc spinlock 4- atomic_plane_update -> a) update vkms_output->primary_crc b) get reference to fb 5- atomic_flush -> a) send vblank event while holding event_lock b) release crc spinlock * hrtimer regular callback: 1- hold crc spinlock 2- drm_crtc_handle_vblank() 3- queue vkms_crc_work_handle 4- release crc spinlock * cleanup: 1- @cleanup_fb ->vunmap vkms_gem_obj->vaddr 2- @crtc_destroy -> flush work struct 3- @plane_destroy -> a) if (fb refcount) remove reference to fb b) deallocate crc_data Signed-off-by: NHaneen Mohammed <hamohammed.sa@gmail.com> [seanpaul fixed typo in vkms_crtc s/vblamk/vblank/] Signed-off-by: NSean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/b948327f48c3e70ab232b4a0848ee6d033b26484.1533171495.git.hamohammed.sa@gmail.com
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