On STM32 DMA3, channels can be reserved, so they are non available for Linux. This non-availability creates a mismatch between dma_chan id and DMA3 channel id. Use dma_async_device_channel_register() to register the channels after controller registration and change the default channel name, so that it can match the name in the Reference Manual and ease requesting a channel thanks to its name. Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxxxxxxx> --- drivers/dma/stm32/stm32-dma3.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/dma/stm32/stm32-dma3.c b/drivers/dma/stm32/stm32-dma3.c index 9249b64a4455..4e932c2931dc 100644 --- a/drivers/dma/stm32/stm32-dma3.c +++ b/drivers/dma/stm32/stm32-dma3.c @@ -1732,9 +1732,6 @@ static int stm32_dma3_probe(struct platform_device *pdev) chan->fifo_size = get_chan_hwcfg(i, G_FIFO_SIZE(i), hwcfgr); /* If chan->fifo_size > 0 then half of the fifo size, else no burst when no FIFO */ chan->max_burst = (chan->fifo_size) ? (1 << (chan->fifo_size + 1)) / 2 : 0; - chan->vchan.desc_free = stm32_dma3_chan_vdesc_free; - - vchan_init(&chan->vchan, dma_dev); } ret = dmaenginem_async_device_register(dma_dev); @@ -1742,14 +1739,26 @@ static int stm32_dma3_probe(struct platform_device *pdev) goto err_clk_disable; for (i = 0; i < ddata->dma_channels; i++) { + char name[12]; + if (chan_reserved & BIT(i)) continue; + chan = &ddata->chans[i]; + snprintf(name, sizeof(name), "dma%dchan%d", ddata->dma_dev.dev_id, chan->id); + + chan->vchan.desc_free = stm32_dma3_chan_vdesc_free; + vchan_init(&chan->vchan, dma_dev); + + ret = dma_async_device_channel_register(&ddata->dma_dev, &chan->vchan.chan, name); + if (ret) { + dev_err_probe(&pdev->dev, ret, "Failed to register channel %s\n", name); + goto err_clk_disable; + } + ret = platform_get_irq(pdev, i); if (ret < 0) goto err_clk_disable; - - chan = &ddata->chans[i]; chan->irq = ret; ret = devm_request_irq(&pdev->dev, chan->irq, stm32_dma3_chan_irq, 0, -- 2.25.1