Hi Sekhar, On 07/10/2017 01:00 PM, Sekhar Nori wrote: > On Thursday 06 July 2017 10:43 PM, Alexandre Bailon wrote: >> On 06/29/2017 03:50 PM, Sekhar Nori wrote: >>> Hi Alexandre, Bin, >>> >>> With latest linux-next, I see a warning dump when I remove g_zero[1] on >>> OMAP-L138 LCDK board. I am building the kernel with davinci_all_defconfig. >>> >>> It is not present in latest mainline because the warnings are introduced >>> with CPPI DMA getting enabled in latest -next. >>> >>> Subsequent insertion of g_ether leads to a warning too[2], although the >>> gadget seems to work (ping test). >>> >>> Since these are pretty annoying, it will be nice to get rid of them. I >>> have not been able to debug any further. But if you have >>> ideas/experiments to try, I can do that. > >> I got a lot of these warnings during development but it was only for the >> host mode. >> If I remember correctly, the cause was a race between the teardown >> function and the interrupt handler. >> The teardwon descriptor was pop from the queue by the interrupt handler, >> preventing cppi41_tear_down_chan() to get it, which will result after >> some retries to a couple of warnings. >> >> I will take a look to see if that is the same issue. That is not the same issue. Still, for some reasons, we never get the teardown descriptor. Two possibilities: - Like the issue I had, the teardown is pop at the wrong place. - The teardown doesn't complete or the descriptor is not queued.
I think we should eliminate the first one before to work on the second one. I think adding some logs to cppi41_pop_desc() could help to figure out what is happening. > > Thanks! I also see similar warnings under fast ping traffic and g_ether > inserted on LCDK. They dont come immediately though. Only after an hour > or so under traffic. I would not have expected to have them during a ping but this probably happens because some USB packet have timed out, which cause may a teardown. > > I can those provide logs too if its going to be helpful. Currently, I think we should focus on the warnings that happens during the rmmod as they are always reproducible. Thanks, Alexandre -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
