[BISECTED REGRESSION] b43legacy broken on G4 PowerBook

Larry Finger Larry.Finger at lwfinger.net
Wed Jun 12 11:57:34 AEST 2019


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



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