From 90f835414067b104d9249e279413dfa65abb99b6 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Fri, 12 Oct 2018 23:57:38 +0900
Subject: [PATCH] mmc: uniphier-sd: avoid using broken DMA RX channel

host->chan_rx is NULL when UNIPHIER_SD_CAP_BROKEN_DMA_RX quirk flag
is set. In this case, it should not set up DMA.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/mmc/host/uniphier-sd.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mmc/host/uniphier-sd.c b/drivers/mmc/host/uniphier-sd.c
index df854a33c81c..91a2be41edf6 100644
--- a/drivers/mmc/host/uniphier-sd.c
+++ b/drivers/mmc/host/uniphier-sd.c
@@ -252,6 +252,9 @@ static void uniphier_sd_internal_dma_start(struct tmio_mmc_host *host,
 	u32 dma_mode;
 	int sg_len;
 
+	if ((data->flags & MMC_DATA_READ) && !host->chan_rx)
+		goto force_pio;
+
 	if (WARN_ON(host->sg_len != 1))
 		goto force_pio;