Date: Sat, 31 Dec 2011 17:03:08 +0100 From: Stefan Bethke <stb@lassitu.de> To: Adrian Chadd <adrian@freebsd.org> Cc: Aleksandr Rybalko <ray@ddteam.net>, freebsd-mips@freebsd.org Subject: Re: arge problem on MR3420 Message-ID: <A50EA4D4-A2BE-49DB-B545-FB2568200135@lassitu.de> In-Reply-To: <CAJ-VmoncaNavvGns9dM_Kc_BiuKNbNpmNijiYKAOh13bQ967Rw@mail.gmail.com> References: <B40E8E4D-115F-46EF-A51F-52E562EF166E@lassitu.de> <CAJ-VmokWLzfjd%2B=_=tSt7ukc=gK2kd9H5s7sH-7bbzSpzBFUcQ@mail.gmail.com> <20111231000638.d257448c.ray@ddteam.net> <98BA8EF5-E808-43F8-92A8-68B14CAF998F@lassitu.de> <2A05E0AA-5AA5-47FD-90EA-BD6B23A01EFE@lassitu.de> <CAJ-VmoncaNavvGns9dM_Kc_BiuKNbNpmNijiYKAOh13bQ967Rw@mail.gmail.com>
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Am 31.12.2011 um 17:01 schrieb Adrian Chadd: > On 31 December 2011 04:36, Stefan Bethke <stb@lassitu.de> wrote: >> Am 30.12.2011 um 23:49 schrieb Stefan Bethke: >> >>> OK, trying to pull in everyone. There seems to be a problem with if_arge on certain chips/platforms. I've encountered it on TL-MR3420 and WRT-160NL. I'm currently working off Adrians gitorious repo. >> >> The problem is limited to BOOTP; if I mount a USB stick as root, I can bring up arge1 without issue. >> >> On the AR7241, arge0 is connected to a phy and the blue WAN port, arge1 is connected to the built-in switch. The port speeds are fixed (1000 for the switch, 100 for the phy). >> >> With BOOTP enabled, I'm getting an interrupt storm on intr 3. I've enabled debugging for arge, and it seems there is a TX underrun that is not being cleared in that case. I'm not fully understanding the code, so I'm not sure why the TX underrun is not being cleared, or keeps reoccurring. > > Is the bootp code somehow tickling the interface setup in a way that > isn't the same as the userland-driven config? > > Ie, a tx underrun should only occur if it runs out of TX descriptor > slots. That's fine, it just means that it go to the end of the > descriptor list. It's not _necessarily_ an error condition. > > And it should only _keep_ occuring if someone/something keeps tickling > the DMA_TX_CONTROL_EN bit. > > So when the underrun occurs, what's the state of the TX ring head/tail pointers? > > The code in arge_intr() should be self explanatory. If any frames were > sent, call arge_start_locked(). The call to arge_encap() throws > something into the TX ring and then sets DMA_TX_CONTROL_EN. > > How about adding a printf() to arge_start_locked() and arge_encap(), > see if they're constantly being called. I'll do that next year :-) I believe the BOOTP code starts before timers are running, would that affect things? Stefan -- Stefan Bethke <stb@lassitu.de> Fon +49 151 14070811
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