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@xxxxxxxxxxxxxxx> --- drivers/dma/dma-jz4780.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c index 96701dedcac8..d63753a56541 100644 --- a/drivers/dma/dma-jz4780.c +++ b/drivers/dma/dma-jz4780.c @@ -938,6 +938,14 @@ static int jz4780_dma_probe(struct platform_device *pdev) jzchan->vchan.desc_free = jz4780_dma_desc_free; } + /* + * On JZ4760, chan0 won't enable properly the first time. + * Enabling then disabling chan1 will magically make chan0 work + * correctly. + */ + jz4780_dma_chan_enable(jzdma, 1); + jz4780_dma_chan_disable(jzdma, 1); + ret = platform_get_irq(pdev, 0); if (ret < 0) goto err_disable_clk; -- 2.33.0
