When blocksize is set to 2352, alwas read 2352 bytes.

This means it might read more than just data, but that is exactly
what we want here (for reading VCD's fx)

sys/dev/ata/atapi-cd.c

@@ -1175,9 +1175,17 @@ acd_start(struct atapi_softc *atp)
 		return;
 	    }
 	}
-	if (blocksize == 2048)
+	switch (blocksize) {
+	case 2048:
 	    ccb[0] = ATAPI_READ_BIG;
-	else {
+	    break;
+
+	case 2352: 
+	    ccb[0] = ATAPI_READ_CD;
+	    ccb[9] = 0xf8;
+	    break;
+
+	default:
 	    ccb[0] = ATAPI_READ_CD;
 	    ccb[9] = 0x10;
 	}