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dmaengine: jz4780: Work around hardware bug on JZ4760 SoCs

The JZ4760 SoC has a hardware problem with chan0 not enabling properly
if it's enabled before chan1, after a reset (works fine afterwards).
This is worked around in the probe function by just enabling then
disabling chan1.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20211206174259.68133-4-paul@crapouillou.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>

authored by

Paul Cercueil and committed by
Vinod Koul b72cbb1a dafa79a1

+8
+8
drivers/dma/dma-jz4780.c
··· 938 938 jzchan->vchan.desc_free = jz4780_dma_desc_free; 939 939 } 940 940 941 + /* 942 + * On JZ4760, chan0 won't enable properly the first time. 943 + * Enabling then disabling chan1 will magically make chan0 work 944 + * correctly. 945 + */ 946 + jz4780_dma_chan_enable(jzdma, 1); 947 + jz4780_dma_chan_disable(jzdma, 1); 948 + 941 949 ret = platform_get_irq(pdev, 0); 942 950 if (ret < 0) 943 951 goto err_disable_clk;