2019-06-12 07:26:28

by Larry Finger

[permalink] [raw]
Subject: Re: [BISECTED REGRESSION] b43legacy broken on G4 PowerBook

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