Re: Regression caused by commit 882164a4a928

From: Matt Redfearn
Date: Wed May 09 2018 - 08:55:33 EST

Hi Larry

On 07/05/18 16:44, Larry Finger wrote:

Although commit 882164a4a928 ("ssb: Prevent build of PCI host features in module") appeared to be harmless, it leads to complete failure of drivers b43. and b43legacy, and likely affects b44 as well. The problem is that CONFIG_SSB_PCIHOST is undefined, which prevents the compilation of the code that controls the PCI cores of the device. See for details.

Sorry for the breakage :-/

As the underlying errors ("pcibios_enable_device" undefined, and "register_pci_controller" undefined) do not appear on the architectures that I have tested (x86_64, x86, and ppc), I suspect something in the arch-specific code for your setup (MIPS?). As I have no idea on how to fix that problem, would the following patch work for you?

diff --git a/drivers/ssb/Kconfig b/drivers/ssb/Kconfig
index 9371651d8017..3743533c8057 100644
--- a/drivers/ssb/Kconfig
+++ b/drivers/ssb/Kconfig
@@ -117,7 +117,7 @@ config SSB_SERIAL

-ÂÂÂÂÂÂ depends on SSB_PCIHOST && SSB = y
+ÂÂÂÂÂÂ depends on SSB_PCIHOST && (SSB = y || !MIPS)
ÂÂÂÂÂÂÂ default y


I believe that the problem stems from these drivers being used for some wireless AP functionality built into some MIPS based SoCs. The Kconfig rules sort out building this additional functionality when configured for MIPS (in a round about sort of way), but it allowed it even when SSB is a module, leading to build failures. My patch was intended to prevent that.

There was a similar issue in the same Kconfig file, introduced by c5611df96804 and fixed by a9e6d44ddecc. It was fixed the same way as you suggest. I've tested the above patch and it does work for MIPS (preventing the PCICORE being built into the module).

Tested-by: Matt Redfearn <matt.redfearn@xxxxxxxx>

Thanks & sorry again for the breakage,