On Tue, May 01, 2012 at 08:13:46PM +0300, Emmanuel Grumbach wrote: > Hi, > > I am not sure the patch will help because the race is _very_ unlikely. > But I would be glad to know if you can reproduce on latest > compat-wireless. > How reproducible is that on 3.3.3 ? Is that 100% ? it seems so. It happens at least once at boot time. I will try wireless-testing and see what happens. Then I will apply your patch. Thanks a lot! > > I guess my machine doesn't have IOMMU, but honestly, I am not sure I > know how to check. > > On Tue, May 1, 2012 at 19:52, Venkataraman, Meenakshi > <meenakshi.venkataraman@xxxxxxxxx> wrote: > > > > Hi John, Antonio, > > > > Emmanuel found a race condition in rx buffer allocation/deallocation, and > > attached is a patch that fixes it. > > > > >> > since linux-3.0 (I don't remember if it was the case even before), > > >> > I'm getting this output in dmesg: > > >> > > > >> > [ 53.662990] ------------[ cut here ]------------ > > >> > [ 53.663016] WARNING: at drivers/iommu/intel-iommu.c:2911 > > >> > intel_unmap_page+0x14b/0x180() > > >> > [ 53.663047] Hardware name: Latitude E5420 > > >> > [ 53.663066] Driver unmaps unmatched page at PFN ffd1a000 > > >> > > >> > > >> I see that I always get the same addr passed to the unmap function: > > >> > > >> [ 23.950535] Driver unmaps unmatched page at PFN ffd1a000 > > >> > > >> is it a coincidence? > > >> I'm running linux-3.3.3 right now. I can try wireless-testing if it > > >> would help. > > > > [MV] Antonio -- can you try out the patch attached and let us know if you > > continue to see the problem? > > > > >Just for the record, we are seeing a similar problem on RHEL 6.3 (which > > > has an > > >iwlwifi driver derived from linux-3.2). > > > > > > https://bugzilla.redhat.com/show_bug.cgi?id=815998 > > > > [MV] John -- I'll update the redhat bugzilla as well. > > > > Thanks > > Meenakshi -- Antonio Quartulli ..each of us alone is worth nothing.. Ernesto "Che" Guevara
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