On Thu, May 23, 2013 at 1:09 PM, Vinod Koul <vinod.k...@intel.com> wrote: > On Tue, May 21, 2013 at 08:24:15PM +0300, Andy Shevchenko wrote: >> On Tue, May 21, 2013 at 6:11 PM, Will Deacon <will.dea...@arm.com> wrote: >> > On Tue, May 21, 2013 at 01:33:17PM +0100, Andy Shevchenko wrote: >> >> When thread is going to be stopped we have to unconditionally terminate >> >> all >> >> ongoing transfers. Otherwise it would be possible that callback function >> >> will >> >> be called on the next interrupt and will try to access to already freed >> >> structures. >> >> >> >> The patch introduces specific error message for this, though it doesn't >> >> increase the counter of the failed tests. >> >> >> > Thanks for persevering with this! Although this patch definitely fixes the >> > panic I was seeing, I now observe buffer verification failures in >> > subsequent >> > test runs after an aborted run: >> >> I think the description to the commit adfa543e "dmatest: don't use >> set_freezable_with_signal()" may shed light on this. >> >> The background (if I got it correctly) is in race with done flag. So, >> we got a callback call from the DMA engine, but we don't know which >> transfer triggers it. >> I might be wrong. This is just an assumption. >> >> Have you ever see such behaviour on pre v3.10-rc1 kernels? (I mean >> with old dmatest module) > Terminate shouldnt cause the issue with buffer verfication, can you try this > on > dw_dmac, do you see similar failures on verfication?
I saw the similar errors on dw_dmac on Intel Medfield device. Anyway, I checked another approach with Will. For now I will send a quick fix that prevents tester to abort an ongoing transfer. In future we could implement a robust logic when transfers can be interrupted at any time. -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
