Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 120/355] MIPS: lantiq: dma: add small delay after reset | Date | Mon, 15 Nov 2021 18:00:44 +0100 |
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From: Aleksander Jan Bajkowski <olek2@wp.pl>
[ 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 aeb1b989cd4ee..24c6267f78698 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 <lantiq_soc.h> @@ -221,6 +222,8 @@ 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); -- 2.33.0
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