On Wed, Jul 23, 2014 at 1:04 PM, Nick Krause <xerofoify@xxxxxxxxx> wrote: > Hey Greg and others. > Sorry for another email but it seems the function, > ion_carveout_heap_unmap_dma is > just returning and not doing anything useful. Furthermore I am new so > I don't known how > to write this function but this may be causing some rather serious > bugs as if the dma heap > is not unmaped and we call this function a lot this will make the > kernel not able to handle dma requests > for this driver and other drivers that need this and in turn lead to > a oops or even a kernel panic due to leaked > dma allocated memory. I would recommend writing this function or > helping me write it in > other to avoid some rather serious bugs without a proper dma unmapping > function for this driver :). > Nick Look at ion_carveout_heap_map_dma - it doesn't do anything, it just returns a pre-existing virtual address. That means there is nothing to do in unmap. map_dma is actually a bit of a misnomer here, as the actual mapping is done in ion_map_dma_buf. All ion_carveout_heap_map_dma does is return the sg table for ion_map_dma_buf to pass to dma_map_sg. _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
