On Sun, 2012-09-16 at 19:07 -0700, Greg KH wrote:
> 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?
This debug interface debug_dma_dump_map_errors() is enabled only when
CONFIG_DMA_API_DEBUG is enabled, however I agree that debugfs is a
better choice than logging to syslog. I created debugfs interfaces for
these error counts at system level. Are recommending the same approach
for per device counts as well?
-- Shuah
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