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

From: Greg KH
Date: Sun Sep 16 2012 - 22:16:53 EST


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
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