On Fri, Dec 05, 2014 at 08:22:05PM +0100, Arend van Spriel wrote: > On 12/05/14 19:28, Catalin Marinas wrote: > >This is solved by using a pre-allocated, pre-mapped atomic_pool which > >avoids any further mapping. __dma_alloc() calls __alloc_from_pool() when > >!__GFP_WAIT. > > So we are actually calling dma_alloc_coherent() with GFP_KERNEL during > device probe. That last paragraph Russell pointed out seems to suggest this > is not allowed. device probe is a schedulable, sleepable context, so dma_alloc_coherent() is fine there. As Catalin points out, and as I realised after sending them ail, it does check for __GFP_WAIT and uses a smaller atomic pool for those allocations. This explains why no one has hit any warnings in map_vm_area. So, it's safe from atomic contexts after all. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
