patches/1232-sh_eth-add-EDMR.NBST-support.patch

From 472236b8c7802c7df26ead68f38d2b1fa20c2197 Mon Sep 17 00:00:00 2001
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Date: Fri, 18 May 2018 21:31:28 +0300
Subject: [PATCH 1232/1795] sh_eth: add EDMR.NBST support

The R-Car V3H (AKA R8A77980) GEther controller adds the DMA burst mode bit
(NBST) in EDMR and the manual tells to always set it before doing any DMA.

Based on the original (and large) patch by Vladimir Barinov.

Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 93f0fa75190fefee55408a1c0812fa54f576c61b)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/net/ethernet/renesas/sh_eth.c | 4 ++++
 drivers/net/ethernet/renesas/sh_eth.h | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index c9060768ffcf..19ebb6e9f91a 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1434,6 +1434,10 @@ static int sh_eth_dev_init(struct net_device *ndev)
 
 	sh_eth_write(ndev, mdp->cd->trscer_err_mask, TRSCER);
 
+	/* DMA transfer burst mode */
+	if (mdp->cd->nbst)
+		sh_eth_modify(ndev, EDMR, EDMR_NBST, EDMR_NBST);
+
 	if (mdp->cd->bculr)
 		sh_eth_write(ndev, 0x800, BCULR);	/* Burst sycle set */
 
diff --git a/drivers/net/ethernet/renesas/sh_eth.h b/drivers/net/ethernet/renesas/sh_eth.h
index 1bf930d4a1e5..6dd24fc515ca 100644
--- a/drivers/net/ethernet/renesas/sh_eth.h
+++ b/drivers/net/ethernet/renesas/sh_eth.h
@@ -184,6 +184,7 @@ enum GECMR_BIT {
 
 /* EDMR */
 enum DMAC_M_BIT {
+	EDMR_NBST = 0x80,
 	EDMR_EL = 0x40, /* Litte endian */
 	EDMR_DL1 = 0x20, EDMR_DL0 = 0x10,
 	EDMR_SRST_GETHER = 0x03,
@@ -505,6 +506,7 @@ struct sh_eth_cpu_data {
 	unsigned bculr:1;	/* EtherC have BCULR */
 	unsigned tsu:1;		/* EtherC have TSU */
 	unsigned hw_swap:1;	/* E-DMAC have DE bit in EDMR */
+	unsigned nbst:1;	/* E-DMAC has NBST bit in EDMR */
 	unsigned rpadir:1;	/* E-DMAC have RPADIR */
 	unsigned no_trimd:1;	/* E-DMAC DO NOT have TRIMD */
 	unsigned no_ade:1;	/* E-DMAC DO NOT have ADE bit in EESR */
-- 
2.19.0