Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Fri, 07 Dec 2018 23:51:41 +0900 (JST)
Message-Id: <20181207.235141.2138062629640003368.anemo@mba.ocn.ne.jp>
To:     geert@linux-m68k.org
Cc:     trond.myklebust@hammerspace.com, linux-nfs@vger.kernel.org,
        linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: NFS/TCP crashes on MIPS/RBTX4927 in v4.20-rcX (bisected)
From:   Atsushi Nemoto <anemo@mba.ocn.ne.jp>
In-Reply-To: <CAMuHMdU9zXXSaPHKvfG3A73h3CTsb9H2RT_gWt-Ne=qQ+HKShQ@mail.gmail.com>
References: <CAMuHMdVJr0PwvJg3FeTCy7vxuyY1=S1tPLHO7hPsoZX4wZ+-cQ@mail.gmail.com>
        <20181205.221146.969453990167463340.anemo@mba.ocn.ne.jp>
        <CAMuHMdU9zXXSaPHKvfG3A73h3CTsb9H2RT_gWt-Ne=qQ+HKShQ@mail.gmail.com>
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, 5 Dec 2018 14:41:30 +0100, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> When using these options, I do see a slowdown in early boot, but the issue
> is still there.

Hmm, the NIC of the board is NE2000 variants, so DMA coherency will
not be an issue anyway.  So strange ...

The board has a PCI slot.  If you had an legacy PCI NIC card, trying
with it might help finding the bug.

> My next guess is an unaligned access not using {get,put}_unaligned(), which
> doesn't seem to work on tx4927, but doesn't cause an exception neither.

IIRC, TX49 can raise an exception on unaligned access.

---
Atsushi Nemoto