From mboxrd@z Thu Jan 1 00:00:00 1970 From: nsekhar@ti.com (Sekhar Nori) Date: Mon, 10 Jul 2017 16:30:24 +0530 Subject: Warning dump on OMAP-L138 when g_zero module is removed In-Reply-To: <260e5199-624d-b402-5481-2d818d282ce7@baylibre.com> References: <748a9491-e834-34cb-993f-e8c7e2538961@ti.com> <260e5199-624d-b402-5481-2d818d282ce7@baylibre.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. 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 can those provide logs too if its going to be helpful. Thanks, Sekhar