diff --git a/src/v4l2.c b/src/v4l2.c
index 7e09ef9..9e2ce8b 100644
--- a/src/v4l2.c
+++ b/src/v4l2.c
@@ -433,7 +433,6 @@ static int v4l2_ioctl_controls(int video_fd, int request_fd, unsigned long ioc,
 			       unsigned int num_controls)
 {
 	struct v4l2_ext_controls controls;
-	int rc;
 
 	memset(&controls, 0, sizeof(controls));
 
@@ -445,24 +444,7 @@ static int v4l2_ioctl_controls(int video_fd, int request_fd, unsigned long ioc,
 		controls.request_fd = request_fd;
 	}
 
-	rc = ioctl(video_fd, ioc, &controls);
-
-	/*
-	 * iter18 α-22 diagnostic: dump error_idx + request_fd after each
-	 * S_EXT_CTRLS to detect silent partial failure (mechanism 5).
-	 * The kernel sets error_idx to the failing control's index or
-	 * count (== num_controls) for "validation passed all" or
-	 * "system-wide failure". Log unconditionally so we can correlate.
-	 */
-	if (ioc == VIDIOC_S_EXT_CTRLS) {
-		request_log("α-22: S_EXT_CTRLS rc=%d errno=%d count=%u "
-			    "error_idx=%u request_fd=%d which=0x%x\n",
-			    rc, rc < 0 ? errno : 0, controls.count,
-			    controls.error_idx, controls.request_fd,
-			    controls.which);
-	}
-
-	return rc;
+	return ioctl(video_fd, ioc, &controls);
 }
 
 int v4l2_get_controls(int video_fd, int request_fd,