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| author | Paul Cercueil <paul@crapouillou.net> | 2021-12-06 17:42:56 +0000 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2021-12-17 21:39:27 +0530 |
| commit | b72cbb1ab2aff3ceef8a2703052d06dc216b01f0 (patch) | |
| tree | 3b3badf385b543fdac03babf3e95f7cf1cfe3440 | |
| parent | dafa79a10ed70683811295cb68deca2d30c22ef4 (diff) | |
| download | lwn-b72cbb1ab2aff3ceef8a2703052d06dc216b01f0.tar.gz lwn-b72cbb1ab2aff3ceef8a2703052d06dc216b01f0.zip | |
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>
| -rw-r--r-- | drivers/dma/dma-jz4780.c | 8 |
1 files changed, 8 insertions, 0 deletions
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; |