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;
Subject: Re: [BISECTED REGRESSION] b43legacy broken on G4 PowerBook
To:     Aaro Koskinen <aaro.koskinen@iki.fi>
Cc:     Christoph Hellwig <hch@lst.de>,
        Christian Zigotzky <chzigotzky@xenosoft.de>,
        Michael Ellerman <mpe@ellerman.id.au>,
        linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org
References: <20190605225059.GA9953@darkstar.musicnaut.iki.fi>
 <73da300c-871c-77ac-8a3a-deac226743ef@lwfinger.net>
 <20190607172902.GA8183@lst.de>
 <30000803-3772-3edf-f4a9-55122d504f3f@lwfinger.net>
 <20190610081825.GA16534@lst.de>
 <153c13f5-a829-1eab-a3c5-fecfb84127ff@lwfinger.net>
 <20190611060521.GA19512@lst.de>
 <5aaa600b-5b59-1f68-454f-20403c318f1a@lwfinger.net>
 <20190611224623.GC26504@darkstar.musicnaut.iki.fi>
From:   Larry Finger <Larry.Finger@lwfinger.net>
Message-ID: <74c8af35-6006-5ca8-0fe4-b5938b1139ff@lwfinger.net>
Date:   Tue, 11 Jun 2019 20:57:34 -0500
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.7.0
MIME-Version: 1.0
In-Reply-To: <20190611224623.GC26504@darkstar.musicnaut.iki.fi>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

On 6/11/19 5:46 PM, Aaro Koskinen wrote:
> Hi,
> 
> On Tue, Jun 11, 2019 at 05:20:12PM -0500, Larry Finger wrote:
>> It is obvious that the case of a mask smaller than min_mask should be
>> handled by the IOMMU. In my system, CONFIG_IOMMU_SUPPORT is selected. All
>> other CONFIG variables containing IOMMU are not selected. When
>> dma_direct_supported() fails, should the system not try for an IOMMU
>> solution? Is the driver asking for the wrong type of memory? It is doing a
>> dma_and_set_mask_coherent() call.
> 
> I don't think we have IOMMU on G4. On G5 it should work (I remember fixing
> b43 issue on G5, see 4c374af5fdee, unfortunately all my G5 Macs with b43
> are dead and waiting for re-capping).

You are right. My configuration has CONFIG_IOMMU_SUPPORT=y, but there is no 
mention of an IOMMU in the log.

Larry