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

[Jon Hunter <jonathanh@nvidia.com>]

On 23/03/2026 08:38, 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@nvidia.com>
> ---
> 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(-)
> 
> diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
> index 14e0c408ed1e..a50cd52fec18 100644
> --- a/drivers/dma/tegra210-adma.c
> +++ b/drivers/dma/tegra210-adma.c
> @@ -335,8 +335,16 @@ static int tegra_adma_request_alloc(struct tegra_adma_chan *tdc,
>   	struct tegra_adma *tdma = tdc->tdma;
>   	unsigned int sreq_index = tdc->sreq_index;
>   
> -	if (tdc->sreq_reserved)
> -		return tdc->sreq_dir == direction ? 0 : -EINVAL;
> +	if (tdc->sreq_reserved) {
> +		if (tdc->sreq_dir != direction) {
> +			dev_err(tdma->dev,
> +				"DMA request direction mismatch: reserved=%s, requested=%s\n",
> +				dmaengine_get_direction_text(tdc->sreq_dir),
> +				dmaengine_get_direction_text(direction));
> +			return -EINVAL;
> +		}
> +		return 0;
> +	}
>   
>   	if (sreq_index > tdma->cdata->ch_req_max) {
>   		dev_err(tdma->dev, "invalid DMA request\n");
> @@ -665,8 +673,11 @@ static int tegra_adma_set_xfer_params(struct tegra_adma_chan *tdc,
>   	const struct tegra_adma_chip_data *cdata = tdc->tdma->cdata;
>   	unsigned int burst_size, adma_dir, fifo_size_shift;
>   
> -	if (desc->num_periods > ADMA_CH_CONFIG_MAX_BUFS)
> +	if (desc->num_periods > ADMA_CH_CONFIG_MAX_BUFS) {
> +		dev_err(tdc2dev(tdc), "invalid DMA periods %zu (max %u)\n",
> +			desc->num_periods, ADMA_CH_CONFIG_MAX_BUFS);
>   		return -EINVAL;
> +	}
>   
>   	switch (direction) {
>   	case DMA_MEM_TO_DEV:
> @@ -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;
> +			}
> +
>   			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;
> +	}
>   
>   	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);

Reviewed-by: Jon Hunter <jonathanh@nvidia.com>

Thanks!
Jon

-- 
nvpublic