From: Aleksander Jan Bajkowski olek2@wp.pl
stable inclusion from stable-5.10.80 commit 5af57ce8a6155fe3e4270d28d171abf8903bebc0 bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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 Signed-off-by: Chen Jun chenjun102@huawei.com Reviewed-by: Weilong Chen chenweilong@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- 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 aeb1b989cd4e..24c6267f7869 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);