Date: Wed, 6 Jun 2001 17:24:05 +0100 From: David Malone <dwmalone@maths.tcd.ie> To: Mitja Horvat <mitja.horvat@hermes.si> Cc: freebsd-stable@freebsd.org Subject: Re: 3Com 3c905B related kernel panic Message-ID: <20010606172405.A57743@walton.maths.tcd.ie> In-Reply-To: <200106061550.f56FomJ00618@lamu.hermes.si>; from mitja.horvat@hermes.si on Wed, Jun 06, 2001 at 05:50:47PM %2B0200 References: <200106061550.f56FomJ00618@lamu.hermes.si>
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On Wed, Jun 06, 2001 at 05:50:47PM +0200, Mitja Horvat wrote: > The diff is not very large, since it includes only these three lines: > + /* increase packet size to allow reception of 802.1q or ISL packets */ > + if (sc->xl_type == XL_TYPE_905B) > + CSR_WRITE_2(sc, XL_W3_MAXPKTSIZE, XL_PACKET_SIZE); > > What is this supposed to do other than panicing my machine? :) The commit was allowing oversized frames so that VLAN tagged frames could get through. From the commit message it sounds like something on your network may be sending big frames. Bill Paul would be the best person to talk to about this - make sure you include all the info you have about the problem if you send him a message. David. Close PR #27742: allow the xl driver to receive VLAN tagged frames by setting the 'max packet size' register in window 3. This only works for cards based on the cyclone or newer chipsets (i.e. it won't work with the original 3c905/boomerang cards). There is a trick which will work with the boomerang, which is to turn on the 'large packets ok' bit in the MAC control register, however this lets the chip accept any frame up to 4K in length, which is larger than the mbuf cluster buffers we use to receive frames. If somebody sends us such a frame and the chip DMAs it to us, it could write past the end of the cluster buffer and clobber something. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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