On Fri, Nov 27, 2009 at 01:40:26PM +1100, Benjamin Herrenschmidt wrote:

On Wed, 2009-11-18 at 17:05 +0000, Mel Gorman wrote:

quoted

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

Why the above ? XICS only exist on PSERIES and select bypass depends in
nasty ways anyways.

You're right. When I made that change, I assumed that a "select foo"
would also resolve the dependencies. It doesn't but I failed to back
this out as being unnecessary.

quoted

 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

The above bits look plenty enough. Can you also stick it next to the
MPIC one ?

They are. I can.

==== 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 <mel[at]csn.ul.ie>
---
 arch/powerpc/platforms/pseries/Kconfig |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index f0e6f28..60d53ed 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig

@@ -2,6 +2,8 @@ config PPC_PSERIES
 	depends on PPC64 && PPC_BOOK3S
 	bool "IBM pSeries & new (POWER5-based) iSeries"
 	select MPIC
+	select PCI_MSI
+	select XICS
 	select PPC_I8259
 	select PPC_RTAS
 	select RTAS_ERROR_LOGGING