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

From: Christoph Hellwig <[email-masked]>
Date: Wed, 12 Jun 2019 08:55:58 +0200

On Tue, Jun 11, 2019 at 05:20:12PM -0500, Larry Finger wrote:
> Your first patch did not work as the configuration does not have 
> CONFIG_ZONE_DMA. As a result, the initial value of min_mask always starts 
> at 32 bits and is taken down to 31 with the maximum pfn minimization. When 
> I forced the initial value of min_mask to 30 bits, the device worked.

Ooops, yes.  But I think we could just enable ZONE_DMA on 32-bit
powerpc.  Crude enablement hack below:

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 8c1c636308c8..1dd71a98b70c 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -372,7 +372,7 @@ config PPC_ADV_DEBUG_DAC_RANGE
 
 config ZONE_DMA
 	bool
-	default y if PPC_BOOK3E_64
+	default y
 
 config PGTABLE_LEVELS
 	int