Actually, that was easy: use MMC_RSP_CRC to determine whether to look for a
valid CRC.
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index a4bda8f..9e51b87 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -919,7 +919,7 @@
 
 	if (host->use_dma)
 		cmdreg |= DMA_EN;
-	if (cmd->opcode != 41)
+	if (cmd->flags & MMC_RSP_CRC)
 		cmdreg |= CCCE;
 
 	host->req_in_progress = 1;