Re: [PATCH v3] dmaengine: tegra210-adma: Add error logging on failure paths

[Frank Li]

On Mon, Mar 23, 2026 at 08:38:58AM +0000, Sheetal wrote:
> Add dev_err/dev_err_probe logging across failure paths to improve
> debuggability of DMA errors during runtime and probe.
>
> Signed-off-by: Sheetal <sheetal@xxxxxxxxxx>
> ---
> Changes in v3:
> - Cast page_no to (unsigned long long) for %llu to fix -Wformat
>   warning on 32-bit builds where resource_size_t is unsigned int
> - Remove redundant dev_err for devm_ioremap_resource failures since
>   the API already logs errors internally.
>
> Changes in v2:
> - Fix format specifier for size_t: use %zu instead of %u for
>   desc->num_periods to resolve -Wformat warning with W=1
>
>  drivers/dma/tegra210-adma.c | 37 +++++++++++++++++++++++++++-------
>  1 file changed, 30 insertions(+), 7 deletions(-)
>
...
> @@ -1047,38 +1058,45 @@ static int tegra_adma_probe(struct platform_device *pdev)
>  	res_page = platform_get_resource_byname(pdev, IORESOURCE_MEM, "page");
>  	if (res_page) {
>  		tdma->ch_base_addr = devm_ioremap_resource(&pdev->dev, res_page);
>  		if (IS_ERR(tdma->ch_base_addr))
>  			return PTR_ERR(tdma->ch_base_addr);
>
>  		res_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "global");
>  		if (res_base) {
>  			resource_size_t page_offset, page_no;
>  			unsigned int ch_base_offset;
>
> -			if (res_page->start < res_base->start)
> +			if (res_page->start < res_base->start) {
> +				dev_err(&pdev->dev, "invalid page/global resource order\n");
>  				return -EINVAL;

It is in probe function, return dev_err_probe(, -EINVAL, ...);
check other place

> +			}
> +
>  			page_offset = res_page->start - res_base->start;
>  			ch_base_offset = cdata->ch_base_offset;
>  			if (!ch_base_offset)
>  				return -EINVAL;
>
>  			page_no = div_u64(page_offset, ch_base_offset);
> -			if (!page_no || page_no > INT_MAX)
> +			if (!page_no || page_no > INT_MAX) {
> +				dev_err(&pdev->dev, "invalid page number %llu\n",
> +					(unsigned long long)page_no);
>  				return -EINVAL;
> +			}
>
>  			tdma->ch_page_no = page_no - 1;
>  			tdma->base_addr = devm_ioremap_resource(&pdev->dev, res_base);
>  			if (IS_ERR(tdma->base_addr))
>  				return PTR_ERR(tdma->base_addr);
>  		}
>  	} else {
>  		/* If no 'page' property found, then reg DT binding would be legacy */
>  		res_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  		if (res_base) {
>  			tdma->base_addr = devm_ioremap_resource(&pdev->dev, res_base);
>  			if (IS_ERR(tdma->base_addr))
>  				return PTR_ERR(tdma->base_addr);
>  		} else {
> +			dev_err(&pdev->dev, "failed to get memory resource\n");
>  			return -ENODEV;
>  		}
>
> @@ -1130,6 +1147,7 @@ static int tegra_adma_probe(struct platform_device *pdev)
>  		tdc->irq = of_irq_get(pdev->dev.of_node, i);
>  		if (tdc->irq <= 0) {
>  			ret = tdc->irq ?: -ENXIO;
> +			dev_err_probe(&pdev->dev, ret, "failed to get IRQ for channel %d\n", i);
>  			goto irq_dispose;
>  		}
>
> @@ -1141,12 +1159,16 @@ static int tegra_adma_probe(struct platform_device *pdev)
>  	pm_runtime_enable(&pdev->dev);
>
>  	ret = pm_runtime_resume_and_get(&pdev->dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		dev_err_probe(&pdev->dev, ret, "runtime PM resume failed\n");
>  		goto rpm_disable;

can you change to use devm_ firtly to elimiate goto first, then change to
use
	return dev_err_probe() pattern


Frank

> +	}
>
>  	ret = tegra_adma_init(tdma);
> -	if (ret)
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to initialize ADMA: %d\n", ret);
>  		goto rpm_put;
> +	}
>
>  	dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
>  	dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
> --
> 2.17.1
>