Hi, On Wed, Jun 04, 2014 at 06:03:36PM +0300, Eli Billauer wrote: > I believe that I need a managed dma_map_single() my own driver, > which doesn't fall in the case of a single use: The driver allocates > its buffers with __get_free_pages() (or the to-be managed version of > it). Then it cuts the allocated memory into smaller buffers (in some > cases, and with certain alignment rules), and then calls > dma_map_single() to do the DMA mapping for each. The buffers are > held along the driver's lifetime, with DMA sync API juggling control > back and forth to the hardware. Note that the DMA is noncoherent. What you are trying to do should work with dma_alloc_noncoherent(). The API allows partial syncs on this memory, so you should be fine. The problem with a devm variant of dma_map_* is that it is too easy to misuse or to use it wrong so that a driver could eat up all available DMA handles on some platforms. Joerg _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
