[PATCH] dmaengine: xilinx: Handle IRQ mapping errors

[PATCH] dmaengine: xilinx: Handle IRQ mapping errors

[Lars-Peter Clausen]

Handle errors when trying to map the IRQ for the DMA channels.

The main motivation here is to be able to handle probe deferral. E.g. when
using DT overlays it is possible that the DMA controller is probed before
interrupt controller, depending on the order in the DT.

In order to support this switch from irq_of_parse_and_map() to
of_irq_get(), which internally does the same, but it will return
EPROBE_DEFER when the interrupt controller is not yet available.

As a result other errors, such as an invalid IRQ specification, or missing
IRQ are also properly handled.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
 drivers/dma/xilinx/xilinx_dma.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 61618148f9d4..cd62bbb50e8b 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -2980,7 +2980,9 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
 	}
 
 	/* Request the interrupt */
-	chan->irq = irq_of_parse_and_map(node, chan->tdest);
+	chan->irq = of_irq_get(node, chan->tdest);
+	if (chan->irq < 0)
+		return dev_err_probe(xdev->dev, chan->irq, "failed to get irq\n");
 	err = request_irq(chan->irq, xdev->dma_config->irq_handler,
 			  IRQF_SHARED, "xilinx-dma-controller", chan);
 	if (err) {
@@ -3054,8 +3056,11 @@ static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA && ret < 0)
 		dev_warn(xdev->dev, "missing dma-channels property\n");
 
-	for (i = 0; i < nr_channels; i++)
-		xilinx_dma_chan_probe(xdev, node);
+	for (i = 0; i < nr_channels; i++) {
+		ret = xilinx_dma_chan_probe(xdev, node);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }
-- 
2.30.2

RE: [PATCH] dmaengine: xilinx: Handle IRQ mapping errors

[Radhey Shyam Pandey]

> -----Original Message-----
> From: Lars-Peter Clausen <lars@metafoo.de>
> Sent: Wednesday, December 8, 2021 5:12 PM
> To: Vinod Koul <vkoul@kernel.org>
> Cc: Michal Simek <michals@xilinx.com>; Radhey Shyam Pandey
> <radheys@xilinx.com>; dmaengine@vger.kernel.org; Lars-Peter Clausen
> <lars@metafoo.de>
> Subject: [PATCH] dmaengine: xilinx: Handle IRQ mapping errors
> 
> Handle errors when trying to map the IRQ for the DMA channels.
> 
> The main motivation here is to be able to handle probe deferral. E.g. when
> using DT overlays it is possible that the DMA controller is probed before
> interrupt controller, depending on the order in the DT.
> 
> In order to support this switch from irq_of_parse_and_map() to of_irq_get(),
> which internally does the same, but it will return EPROBE_DEFER when the
> interrupt controller is not yet available.
> 
> As a result other errors, such as an invalid IRQ specification, or missing IRQ are
> also properly handled.
> 
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Thanks!
> ---
>  drivers/dma/xilinx/xilinx_dma.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
> index 61618148f9d4..cd62bbb50e8b 100644
> --- a/drivers/dma/xilinx/xilinx_dma.c
> +++ b/drivers/dma/xilinx/xilinx_dma.c
> @@ -2980,7 +2980,9 @@ static int xilinx_dma_chan_probe(struct
> xilinx_dma_device *xdev,
>  	}
> 
>  	/* Request the interrupt */
> -	chan->irq = irq_of_parse_and_map(node, chan->tdest);
> +	chan->irq = of_irq_get(node, chan->tdest);
> +	if (chan->irq < 0)
> +		return dev_err_probe(xdev->dev, chan->irq, "failed to get
> irq\n");
>  	err = request_irq(chan->irq, xdev->dma_config->irq_handler,
>  			  IRQF_SHARED, "xilinx-dma-controller", chan);
>  	if (err) {
> @@ -3054,8 +3056,11 @@ static int xilinx_dma_child_probe(struct
> xilinx_dma_device *xdev,
>  	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA && ret <
> 0)
>  		dev_warn(xdev->dev, "missing dma-channels property\n");
> 
> -	for (i = 0; i < nr_channels; i++)
> -		xilinx_dma_chan_probe(xdev, node);
> +	for (i = 0; i < nr_channels; i++) {
> +		ret = xilinx_dma_chan_probe(xdev, node);
> +		if (ret)
> +			return ret;
> +	}
> 
>  	return 0;
>  }
> --
> 2.30.2

Re: [PATCH] dmaengine: xilinx: Handle IRQ mapping errors

[Vinod Koul]

On 08-12-21, 12:42, Lars-Peter Clausen wrote:
> Handle errors when trying to map the IRQ for the DMA channels.
> 
> The main motivation here is to be able to handle probe deferral. E.g. when
> using DT overlays it is possible that the DMA controller is probed before
> interrupt controller, depending on the order in the DT.
> 
> In order to support this switch from irq_of_parse_and_map() to
> of_irq_get(), which internally does the same, but it will return
> EPROBE_DEFER when the interrupt controller is not yet available.
> 
> As a result other errors, such as an invalid IRQ specification, or missing
> IRQ are also properly handled.

Applied, thanks

-- 
~Vinod