Date: Mon, 11 Nov 2013 16:03:59 +0100 From: Lars Engels <lars.engels@0x20.net> To: freebsd-current@freebsd.org Subject: Re: iwn(4) hangs after r257133 Message-ID: <751d83f294765dbf0c213e18e8eb721b@mail.0x20.net> In-Reply-To: <20131111081857.GA1809@mole.fafoe.narf.at> References: <CALBk6yJf%2BZ_%2BF8kVPFOdQ%2B8UC3vBU3MZJGjkPfxeSkjSZ6FPbA@mail.gmail.com> <20131110121737.GA1834@mole.fafoe.narf.at> <CAJ-Vmom-57ZM0xsxLpL=prENzZ0j27jYNnMLk-_=HHONr3L8zA@mail.gmail.com> <20131110163340.GA1778@mole.fafoe.narf.at> <CAJ-VmonxB-to30Tkq9ad830FTRpbW2=cn9nuNzXHMK67jCuNgQ@mail.gmail.com> <20131110193421.GB1778@mole.fafoe.narf.at> <CAJ-Vmon8E28qDHZ0NzTapob_YCRfDOikkYZGOjki=NA2LtwGdg@mail.gmail.com> <20131111081857.GA1809@mole.fafoe.narf.at>
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Am 11.11.2013 09:18, schrieb Stefan Farfeleder: > On Sun, Nov 10, 2013 at 02:01:12PM -0800, Adrian Chadd wrote: >> Yes. So one of the.. unfortunately broken things in iwn is the ampdu >> tx >> code doesn't do retransmits. So if amrr picks a rate that fails to >> transmit >> everything, the driver doesn't retransmit them. It frees them. >> >> Now when amrr is enabled the hardware will retry at lower rates until >> something succeeds. But it still doesn't retransmit things. I believe >> it >> should be. >> >> So yes its more broken with Mrr disabled. But enabling mrr doesn't fix >> it. >> It just makes it less broken. Someone needs to implement ampdu >> retransmit. >> >> The latest iwn code in head at least tells the rate selection code >> that a >> total ampdu tx failure occured. This BTW is one of the hangs I fixed - >> if >> you hit a point where you never successfully transmitted an ampdu at a >> rate >> the rate would never be decreased. >> >> Now to be clear. I won't be in implementing ampdu retransmit. I'll >> maybe >> fix last multi rate retry once the new hardware support is in. I would >> really appreciate help here with these. Everyone with iwn hardware >> will >> appreciate it :) > > In the mean time, wouldn't it make sense to disable ampdu tx in iwn > then? Or to disallow the combination Mrr + ampdu? Yes, please. I'm also encountering this.
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