[3.16.y-ckt stable] Patch "x86/apic: Re-enable PCI_MSI support for non-SMP X86_32" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    x86/apic: Re-enable PCI_MSI support for non-SMP X86_32

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From c32eddad3e16e48402c499edbd9d8c47401641c8 Mon Sep 17 00:00:00 2001
From: Bryan O'Donoghue <pure.logic at nexus-software.ie>
Date: Thu, 22 Jan 2015 22:58:49 +0000
Subject: x86/apic: Re-enable PCI_MSI support for non-SMP X86_32

commit 38a1dfda8e77d7ba74c94d06d8bc41ba98a4bc8c upstream.

Commit 0dbc6078c06bc0 ('x86, build, pci: Fix PCI_MSI build on !SMP')
introduced the dependency that X86_UP_APIC is only available when
PCI_MSI is false. This effectively prevents PCI_MSI support on 32bit
UP systems because it disables both APIC and IO-APIC. But APIC support
is architecturally required for PCI_MSI.

The intention of the patch was to enforce APIC support when PCI_MSI is
enabled, but failed to do so.

Remove the !PCI_MSI dependency from X86_UP_APIC and enforce
X86_UP_APIC when PCI_MSI support is enabled on 32bit UP systems.

[ tglx: Massaged changelog ]

Fixes 0dbc6078c06bc0 'x86, build, pci: Fix PCI_MSI build on !SMP'
Signed-off-by: Bryan O'Donoghue <pure.logic at nexus-software.ie>
Suggested-by: Thomas Gleixner <tglx at linutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko at gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Link: http://lkml.kernel.org/r/1421967529-9037-1-git-send-email-pure.logic@nexus-software.ie
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/x86/Kconfig | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 27adfd902c6f..12c8ea635f4d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -805,7 +805,7 @@ source "kernel/Kconfig.preempt"

 config X86_UP_APIC
 	bool "Local APIC support on uniprocessors"
-	depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
+	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 	---help---
 	  A local APIC (Advanced Programmable Interrupt Controller) is an
 	  integrated interrupt controller in the CPU. If you have a single-CPU
@@ -816,6 +816,10 @@ config X86_UP_APIC
 	  performance counters), and the NMI watchdog which detects hard
 	  lockups.

+config X86_UP_APIC_MSI
+	def_bool y
+	select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
+
 config X86_UP_IOAPIC
 	bool "IO-APIC support on uniprocessors"
 	depends on X86_UP_APIC
--
2.1.4