On Wed, Jul 23, 2014 at 4:10 PM, Colin Cross <ccross@xxxxxxxxxxx> wrote: > 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. Very well then I guess this is closed then. Cheers Nick _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
