From 6a5b3f5dfb02e2ce9f0c98e74b18b7d1ad9cf13d Mon Sep 17 00:00:00 2001
From: Aleksander Jan Bajkowski <olek2@wp.pl>
Date: Tue, 14 Sep 2021 23:20:58 +0200
Subject: [PATCH] MIPS: lantiq: dma: add small delay after reset

[ Upstream commit c12aa581f6d5e80c3c3675ab26a52c2b3b62f76e ]

Reading the DMA registers immediately after the reset causes
Data Bus Error. Adding a small delay fixes this issue.

Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/lantiq/xway/dma.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/mips/lantiq/xway/dma.c b/arch/mips/lantiq/xway/dma.c
index 63dccb2..2784715 100644
--- a/arch/mips/lantiq/xway/dma.c
+++ b/arch/mips/lantiq/xway/dma.c
@@ -11,6 +11,7 @@
 #include <linux/export.h>
 #include <linux/spinlock.h>
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/of.h>
 
@@ -222,6 +223,8 @@ ltq_dma_init(struct platform_device *pdev)
 	clk_enable(clk);
 	ltq_dma_w32_mask(0, DMA_RESET, LTQ_DMA_CTRL);
 
+	usleep_range(1, 10);
+
 	/* disable all interrupts */
 	ltq_dma_w32(0, LTQ_DMA_IRNEN);
 
-- 
2.7.4