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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
        Simon Horman <horms+renesas@verge.net.au>,
        Vinod Koul <vinod.koul@intel.com>,
        Sasha Levin <alexander.levin@microsoft.com>
Subject: [PATCH 4.14 161/496] dmaengine: rcar-dmac: fix max_chunk_size for R-Car Gen3
Date:   Mon, 28 May 2018 11:59:06 +0200
Message-Id: <20180528100326.661781985@linuxfoundation.org>
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4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

[ Upstream commit d716d9b702bb759dd6fb50804f10a174bd156d71 ]

According to R-Car Gen3 Rev.0.80 manual, the DMATCR can be set to
16,777,215 as maximum. So, this patch fixes the max_chunk_size for
safety on all of SoCs. Otherwise, a system may hang if the DMATCR
is set to 0 on R-Car Gen3.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/dma/sh/rcar-dmac.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -880,7 +880,7 @@ rcar_dmac_chan_prep_sg(struct rcar_dmac_
 
 	rcar_dmac_chan_configure_desc(chan, desc);
 
-	max_chunk_size = (RCAR_DMATCR_MASK + 1) << desc->xfer_shift;
+	max_chunk_size = RCAR_DMATCR_MASK << desc->xfer_shift;
 
 	/*
 	 * Allocate and fill the transfer chunk descriptors. We own the only