From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: Tue, 19 Mar 2019 11:12:59 +0100
Subject: mmc: renesas_sdhi: limit block count to 16 bit for old revisions
Git-commit: c9a9497ccef205ed4ed2e247011382627876d831
Patch-mainline: v5.1-rc2
References: git-fixes

R-Car Gen2 has two different SDHI incarnations in the same chip. The
older one does not support the recently introduced 32 bit register
access to the block count register. Make sure we use this feature only
after the first known version.

Thanks to the Renesas Testing team for this bug report!

Fixes: 5603731a15ef ("mmc: tmio: fix access width of Block Count Register")
Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Tested-by: Phong Hoang <phong.hoang.wz@renesas.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 drivers/mmc/host/sh_mobile_sdhi.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -561,6 +561,7 @@ static int sh_mobile_sdhi_probe(struct p
 	struct tmio_mmc_host *host;
 	struct resource *res;
 	int irq, ret, i;
+	u16 ver;
 	struct tmio_mmc_dma *dma_priv;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -672,6 +673,11 @@ static int sh_mobile_sdhi_probe(struct p
 	if (ret < 0)
 		goto efree;
 
+	ver = sd_ctrl_read16(host, CTL_VERSION);
+	/* GEN2_SDR104 is first known SDHI to use 32bit block count */
+	if (ver < SDHI_VER_GEN2_SDR104 && mmc_data->max_blk_count > U16_MAX)
+		mmc_data->max_blk_count = U16_MAX;
+
 	/* Enable tuning iff we have an SCC and a supported mode */
 	if (of_data && of_data->scc_offset &&
 	    (host->mmc->caps & MMC_CAP_UHS_SDR104 ||