This patch implements a callback function which will be called before crc read. In this function driver can implement any preparation work required for successfully reading CRC data. Changes Since V1: - rebase Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Signed-off-by: Mahesh Kumar <mahesh1.kumar@xxxxxxxxx> --- drivers/gpu/drm/drm_debugfs_crc.c | 8 ++++++++ include/drm/drm_crtc.h | 14 ++++++++++++++ 2 files changed, 22 insertions(+) diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c index 00e743153e94..e303c194c080 100644 --- a/drivers/gpu/drm/drm_debugfs_crc.c +++ b/drivers/gpu/drm/drm_debugfs_crc.c @@ -274,6 +274,14 @@ static ssize_t crtc_crc_read(struct file *filep, char __user *user_buf, return 0; } + if (crtc->funcs->pre_crc_read) { + ret = crtc->funcs->pre_crc_read(crtc); + if (ret) { + spin_unlock_irq(&crc->lock); + return ret; + } + } + /* Nothing to read? */ while (crtc_crc_data_count(crc) == 0) { if (filep->f_flags & O_NONBLOCK) { diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index b21437bc95bf..19c2bf63935e 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -761,6 +761,20 @@ struct drm_crtc_funcs { */ int (*verify_crc_source)(struct drm_crtc *crtc, const char *source, size_t *values_cnt); + /** + * @pre_crc_read: + * + * Driver callback for performing any preparation work required by + * driver before reading CRC + * + * This callback is optional if the driver does not support CRC + * generation or no prework is required before reading the crc + * + * RETURNS: + * + * 0 on success or a negative error code on failure. + */ + int (*pre_crc_read)(struct drm_crtc *crtc); /** * @get_crc_sources: * -- 2.16.2 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel