diff options
Diffstat (limited to 'drivers/gpu/drm/drm_debugfs_crc.c')
| -rw-r--r-- | drivers/gpu/drm/drm_debugfs_crc.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c index 7ca486d750e9..be1b7ba92ffe 100644 --- a/drivers/gpu/drm/drm_debugfs_crc.c +++ b/drivers/gpu/drm/drm_debugfs_crc.c @@ -66,9 +66,18 @@ * the reported CRCs of frames that should have the same contents. * * On the driver side the implementation effort is minimal, drivers only need to - * implement &drm_crtc_funcs.set_crc_source. The debugfs files are automatically - * set up if that vfunc is set. CRC samples need to be captured in the driver by - * calling drm_crtc_add_crc_entry(). + * implement &drm_crtc_funcs.set_crc_source and &drm_crtc_funcs.verify_crc_source. + * The debugfs files are automatically set up if those vfuncs are set. CRC samples + * need to be captured in the driver by calling drm_crtc_add_crc_entry(). + * Depending on the driver and HW requirements, &drm_crtc_funcs.set_crc_source + * may result in a commit (even a full modeset). + * + * CRC results must be reliable across non-full-modeset atomic commits, so if a + * commit via DRM_IOCTL_MODE_ATOMIC would disable or otherwise interfere with + * CRC generation, then the driver must mark that commit as a full modeset + * (drm_atomic_crtc_needs_modeset() should return true). As a result, to ensure + * consistent results, generic userspace must re-setup CRC generation after a + * legacy SETCRTC or an atomic commit with DRM_MODE_ATOMIC_ALLOW_MODESET. */ static int crc_control_show(struct seq_file *m, void *data) |