Received-SPF: pass (google.com: best guess record for domain of linux-wireless-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Message-ID: <d87ac9a7faac0d5522cb496d74afc586410fed9c.camel@kernel.crashing.org>
Subject: Re: [BISECTED REGRESSION] b43legacy broken on G4 PowerBook
From:   Benjamin Herrenschmidt <benh@kernel.crashing.org>
To:     Aaro Koskinen <aaro.koskinen@iki.fi>
Cc:     Christoph Hellwig <hch@lst.de>,
        Christian Zigotzky <chzigotzky@xenosoft.de>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Larry Finger <Larry.Finger@lwfinger.net>,
        linuxppc-dev@lists.ozlabs.org, linux-wireless@vger.kernel.org,
        linux-kernel@vger.kernel.org
Date:   Thu, 06 Jun 2019 20:56:54 +1000
In-Reply-To: <20190606093149.GA11598@darkstar.musicnaut.iki.fi>
References: <20190605225059.GA9953@darkstar.musicnaut.iki.fi>
         <dfe6451c93574b61d4bdde4a05c5f8ccf86b31a0.camel@kernel.crashing.org>
         <20190606093149.GA11598@darkstar.musicnaut.iki.fi>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

On Thu, 2019-06-06 at 12:31 +0300, Aaro Koskinen wrote:
> Hi,
> 
> On Thu, Jun 06, 2019 at 10:54:51AM +1000, Benjamin Herrenschmidt
> wrote:
> > On Thu, 2019-06-06 at 01:50 +0300, Aaro Koskinen wrote:
> > > Hi,
> > > 
> > > When upgrading from v5.0 -> v5.1 on G4 PowerBook, I noticed WLAN
> > > does
> > > not work anymore:
> > > 
> > > [   42.004303] b43legacy-phy0: Loading firmware version 0x127,
> > > patch level 14 (2005-04-18 02:36:27)
> > > [   42.184837] b43legacy-phy0 debug: Chip initialized
> > > [   42.184873] b43legacy-phy0 ERROR: The machine/kernel does not
> > > support the required 30-bit DMA mask
> > > 
> > > The same happens with the current mainline.
> > 
> > How much RAM do you have ?
> 
> The system has 1129 MB RAM. Booting with mem=1G makes it work.

Wow... that's an odd amount. One thing we could possibly do is add code
to limit the amount of RAM when we detect that device....

Cheers,
Ben.