Hi Mathias, Andy, On Thu, Jun 07, 2018 at 10:40:03AM +0300, Mathias Nyman wrote: > On 06.06.2018 19:45, Sudip Mukherjee wrote: > > Hi Andy, > > > > And we meet again. :) > > > > On Wed, Jun 06, 2018 at 06:36:35PM +0300, Andy Shevchenko wrote: > > > On Wed, 2018-06-06 at 17:12 +0300, Mathias Nyman wrote: > > > > On 04.06.2018 18:28, Sudip Mukherjee wrote: > > > > > On Thu, May 24, 2018 at 04:35:34PM +0300, Mathias Nyman wrote: > > > > > > > > > > > > > Odd and unlikely, but to me this looks like some issue in allocating > > > > dma memory > > > > from pool using dma_pool_zalloc() > > > > > > > > > > > > Here's the story: > > > > Sudip sees usb issues on a Intel Atom based board with 4.14.2 kernel. > > > > All tracing points to dma_pool_zalloc() returning the same dma address > > > > block on > > > > consecutive calls. > > > > > > > > In the failing case dma_pool_zalloc() is called 3 - 6us apart. > > > > > > > > <...>-26362 [002] .... 1186.756739: xhci_ring_mem_detail: MATTU > > > > xhci_segment_alloc dma @ 0x000000002d92b000 > > > > <...>-26362 [002] .... 1186.756745: xhci_ring_mem_detail: MATTU > > > > xhci_segment_alloc dma @ 0x000000002d92b000 > > > > <...>-26362 [002] .... 1186.756748: xhci_ring_mem_detail: MATTU > > > > xhci_segment_alloc dma @ 0x000000002d92b000 > > > > > > > > dma_pool_zalloc() is called from xhci_segment_alloc() in > > > > drivers/usb/host/xhci-mem.c > > > > see: > > > > https://elixir.bootlin.com/linux/v4.14.2/source/drivers/usb/host/xhci- > > > > mem.c#L52 > > > > > > > > prints above are custom traces added right after dma_pool_zalloc() > > > > > > For better understanding it would be good to have dma_pool_free() calls > > > debugged as well. > > > > Sudip has a full (394M unpacked) trace at: > https://drive.google.com/open?id=1h-3r-1lfjg8oblBGkzdRIq8z3ZNgGZx- > <snip> > But then it gets stuck, for the whole ring2 dma_pool_zalloc() just returns the same dma address as the last segment for > ring1:0x2d92b000. Last part of trace snippet is just another ring being freed. A gentle ping on this. Any idea on what the problem might be and any possible fix? -- regards Sudip -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
