On Wed, Nov 18, 2009 at 05:05:32PM +1100, Benjamin Herrenschmidt wrote:

On Tue, 2009-11-17 at 12:07 +0000, Mel Gorman wrote:

quoted

KConfig doesn't require CONFIG_XICS to be set with CONFIG_PSERIES but if
it's not set, there are numerous small build errors. This is a small series
of patches to allow CONFIG_XICS to be unset in the config.

XICS appears to be some sort of interrupt controller but I'm not sure how
common it is on systems that require CONFIG_PSERIES. If CONFIG_PSERIES
universally requires CONFIG_XICS, the better path might be to force it to
be set.

Testing was building with make oldconfig a configuration from 2.6.31 on
a PPC970.

CONFIG_XICS should be made invisible and selected by PSERIES.

Like so?

==== CUT HERE ====

powerpc: Add Kconfig dependency on PCI_MSI for XICS and select for PSERIES

It's possible to set CONFIG_XICS without CONFIG_PCI_MSI. When that
happens, the kernel fails to build with

arch/powerpc/platforms/built-in.o: In function `.xics_startup':
xics.c:(.text+0x12f60): undefined reference to `.unmask_msi_irq'
make: *** [.tmp_vmlinux1] Error 1

Furthermore, as noted by Benjamin Herrenschmidt, "CONFIG_XICS should be
made invisible and selected by PSERIES."

This patch adds the dependency in KConfig for XICS on PCI_MSI. When
PSERIES support is being configured, both options are silently selected.

Signed-off-by: Mel Gorman <redacted>
--- 
 arch/powerpc/platforms/Kconfig         |    4 ++--
 arch/powerpc/platforms/pseries/Kconfig |    2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 04a8061..a82c470 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig

@@ -52,9 +52,9 @@ config PPC_UDBG_BEAT
 	default n
 
 config XICS
-	depends on PPC_PSERIES
+	depends on PCI_MSI
 	bool
-	default y
+	default n
 
 config IPIC
 	bool

diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index f0e6f28..81c2289 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig

@@ -5,6 +5,8 @@ config PPC_PSERIES
 	select PPC_I8259
 	select PPC_RTAS
 	select RTAS_ERROR_LOGGING
+	select PCI_MSI
+	select XICS
 	select PPC_UDBG_16550
 	select PPC_NATIVE
 	select PPC_PCI_CHOICE if EMBEDDED