Re: [PATCH] dmaengine: omap-dma: Fix dynamic lch_map alocation

[Peter Ujfalusi]

I have typo in the subject line: s/alocation/allocation ...

Vinod: can you fix it up or should I resend?

-- 
Péter

On 01/02/2017 12:07 PM, Peter Ujfalusi wrote:
> The original patch did not done what it was supposed to be doing and even
> worst it broke legacy boot (OMAP1).
> 
> The lch_map size should be the number of available logical channels in sDMA
> and the od->dma_requests should store the number of available DMA request
> lines usable in sDMA.
> 
> In legacy mode we do not have a way to get the DMA request count, in that
> case we use OMAP_SDMA_REQUESTS (127), despite the fact that OMAP1510 have
> only 31 DMA request line.
> 
> Fixes: 2d1a9a946fae ("dmaengine: omap-dma: Dynamically allocate memory for lch_map")
> Reported-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx   # v4.9
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> ---
>  drivers/dma/omap-dma.c | 30 +++++++++++++++++++++---------
>  1 file changed, 21 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
> index ac68666cd3f4..4ad101a47e0a 100644
> --- a/drivers/dma/omap-dma.c
> +++ b/drivers/dma/omap-dma.c
> @@ -1452,6 +1452,7 @@ static int omap_dma_probe(struct platform_device *pdev)
>  	struct omap_dmadev *od;
>  	struct resource *res;
>  	int rc, i, irq;
> +	u32 lch_count;
>  
>  	od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
>  	if (!od)
> @@ -1494,20 +1495,31 @@ static int omap_dma_probe(struct platform_device *pdev)
>  	spin_lock_init(&od->lock);
>  	spin_lock_init(&od->irq_lock);
>  
> -	if (!pdev->dev.of_node) {
> -		od->dma_requests = od->plat->dma_attr->lch_count;
> -		if (unlikely(!od->dma_requests))
> -			od->dma_requests = OMAP_SDMA_REQUESTS;
> -	} else if (of_property_read_u32(pdev->dev.of_node, "dma-requests",
> -					&od->dma_requests)) {
> +	/* Number of DMA requests */
> +	od->dma_requests = OMAP_SDMA_REQUESTS;
> +	if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
> +						      "dma-requests",
> +						      &od->dma_requests)) {
>  		dev_info(&pdev->dev,
>  			 "Missing dma-requests property, using %u.\n",
>  			 OMAP_SDMA_REQUESTS);
> -		od->dma_requests = OMAP_SDMA_REQUESTS;
>  	}
>  
> -	od->lch_map = devm_kcalloc(&pdev->dev, od->dma_requests,
> -				   sizeof(*od->lch_map), GFP_KERNEL);
> +	/* Number of available logical channels */
> +	if (!pdev->dev.of_node) {
> +		lch_count = od->plat->dma_attr->lch_count;
> +		if (unlikely(!lch_count))
> +			lch_count = OMAP_SDMA_CHANNELS;
> +	} else if (of_property_read_u32(pdev->dev.of_node, "dma-channels",
> +					&lch_count)) {
> +		dev_info(&pdev->dev,
> +			 "Missing dma-channels property, using %u.\n",
> +			 OMAP_SDMA_CHANNELS);
> +		lch_count = OMAP_SDMA_CHANNELS;
> +	}
> +
> +	od->lch_map = devm_kcalloc(&pdev->dev, lch_count, sizeof(*od->lch_map),
> +				   GFP_KERNEL);
>  	if (!od->lch_map)
>  		return -ENOMEM;
>  
>