On Wed, Jul 27, 2016 at 02:32:58PM -0700, Viresh Kumar wrote: > The DMA device can't be registered if it doesn't have any channels > registered at all. Moreover, it leads to memory leak and is reported by > kmemleak as (on 3.10 kernel, and same shall happen on mainline): > > unreferenced object 0xffffffc09e597240 (size 64): > comm "swapper/0", pid 1, jiffies 4294877736 (age 7060.280s) > hex dump (first 32 bytes): > 00 00 00 00 c0 ff ff ff 30 00 00 ff 00 00 00 ff ........0....... > 00 00 00 ff 00 00 00 ff 00 00 00 ff 00 00 00 ff ................ > backtrace: > [<ffffffc0003079ec>] create_object+0x148/0x2a0 > [<ffffffc000cc150c>] kmemleak_alloc+0x80/0xbc > [<ffffffc000303a7c>] kmem_cache_alloc_trace+0x120/0x1ac > [<ffffffc00054771c>] dma_async_device_register+0x160/0x46c > [<ffffffc000548958>] foo_probe+0x1a0/0x264 > [<ffffffc0005d6658>] platform_drv_probe+0x14/0x20 > [<ffffffc0005d50cc>] driver_probe_device+0x160/0x374 > [<ffffffc0005d538c>] __driver_attach+0x60/0x90 > [<ffffffc0005d3e78>] bus_for_each_dev+0x7c/0xb0 > [<ffffffc0005d4a0c>] driver_attach+0x1c/0x28 > [<ffffffc0005d459c>] bus_add_driver+0x124/0x248 > [<ffffffc0005d59cc>] driver_register+0x90/0x110 > [<ffffffc0005d6bf4>] platform_driver_register+0x58/0x64 > [<ffffffc00142a70c>] foo_driver_init+0x10/0x1c > [<ffffffc000200878>] do_one_initcall+0xac/0x148 > [<ffffffc00140096c>] kernel_init_freeable+0x1a0/0x258 > > Return -ENODEV from dma_async_device_register() on such a case. Applied, thanks -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
