Re: [PATCH] dma-debug: New interfaces to debug dma mapping errors

[Greg KH <greg@kroah.com>]

On Sun, Sep 16, 2012 at 06:52:51PM -0600, Shuah Khan wrote:
> +void debug_dma_dump_map_errors(struct device *dev, int all)
> +{
> +	if (all) {
> +		dev_info(dev,
> +			 "DMA-API: DMA map error summary:\n"
> +			 "DMA map errors returned = %d\n"
> +			 "DMA map errors not checked = %d\n"
> +			 "DMA unmap errors = %d\n"
> +			 "SWIOTLB overflow triggers = %d\n",
> +			 dev->dma_map_errors,
> +			 dev->dma_map_errors_not_checked,
> +			 dev->dma_unmap_errors,
> +			 dev->iotlb_overflow_cnt);
> +		return;
> +	}
> +
> +	if (dev->dma_map_errors_not_checked) {
> +		dev_err(dev,
> +			"DMA-API: Driver failed to check\n"
> +			"%d out of a total of %d DMA map errors returned\n"
> +			"by DMA mapping interfaces\n",
> +			dev->dma_map_errors_not_checked,
> +			dev->dma_map_errors);
> +	}
> +
> +	if (dev->dma_unmap_errors) {
> +		dev_err(dev,
> +			"DMA-API: Driver tried to free invalid\n"
> +			"DMA addresses %d times\n",
> +			dev->dma_unmap_errors);
> +	}
> +
> +	if (dev->iotlb_overflow_cnt) {
> +		dev_err(dev,
> +			"DMA-API: SWIOTLB overflow buffer triggered %d times\n",
> +			dev->iotlb_overflow_cnt);
> +	}
> +}
> +EXPORT_SYMBOL(debug_dma_dump_map_errors);

Don't use syslog for stuff like this, that's not good.  Why not use
debugfs?

greg k-h