dmaengine: rcar-dmac: fix max_chunk_size for R-Car Gen3

BugLink: https://bugs.launchpad.net/bugs/1775771

[ Upstream commit d716d9b7 ]

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>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/dma/sh/rcar-dmac.c

@@ -851,7 +851,7 @@ rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl,
 
 	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