Re: [BISECTED REGRESSION] b43legacy broken on G4 PowerBook

[Larry Finger]

This is a multi-part message in MIME format.
On 6/5/19 5:50 PM, 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.
>
> Bisected to:
>
> 	commit 65a21b71f948406201e4f62e41f06513350ca390
> 	Author: Christoph Hellwig <hch@xxxxxx>
> 	Date:   Wed Feb 13 08:01:26 2019 +0100
>
> 	    powerpc/dma: remove dma_nommu_dma_supported
>
> 	    This function is largely identical to the generic version used
> 	    everywhere else.  Replace it with the generic version.
>
> 	    Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> 	    Tested-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>
> 	    Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

Aaro,

Please try the attached patch. I'm not really pleased with it and I will 
continue to determine why the fallback to a 30-bit mask fails, but at least this 
one works for me.

Larry