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authorPaul Cercueil <paul@crapouillou.net>2021-12-06 18:42:56 +0100
committerVinod Koul <vkoul@kernel.org>2021-12-17 17:09:27 +0100
commitb72cbb1ab2aff3ceef8a2703052d06dc216b01f0 (patch)
tree3b3badf385b543fdac03babf3e95f7cf1cfe3440 /drivers/dma
parentdt-bindings: dma: ingenic: Support #dma-cells = <3> (diff)
downloadlinux-b72cbb1ab2aff3ceef8a2703052d06dc216b01f0.tar.xz
linux-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>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/dma-jz4780.c8
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;