1 files changed, 53 insertions, 0 deletions

diff --git a/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.2/0098-intel-idle-Make-idle-driver-more-robust.patch b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.2/0098-intel-idle-Make-idle-driver-more-robust.patch
new file mode 100644
index 00000000..b800a3ea
--- /dev/null
+++ b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.2/0098-intel-idle-Make-idle-driver-more-robust.patch
@@ -0,0 +1,53 @@
+From 1ca189655bf3edf14c4837eba5873fc9c50f7e15 Mon Sep 17 00:00:00 2001
+From: Thomas Renninger <trenn@suse.de>
+Date: Sun, 4 Dec 2011 22:17:29 +0100
+Subject: [PATCH 098/130] intel idle: Make idle driver more robust
+
+commit 5c2a9f06a9cd7194f884cdc88144866235dec07d upstream.
+
+kvm -cpu host passes the original cpuid info to the guest.
+
+Latest kvm version seem to return true for mwait_leaf cpuid
+function on recent Intel CPUs. But it does not return mwait
+C-states (mwait_substates), instead zero is returned.
+
+While real CPUs seem to always return non-zero values, the intel
+idle driver should not get active in kvm (mwait_substates == 0)
+case and bail out.
+Otherwise a Null pointer exception will happen later when the
+cpuidle subsystem tries to get active:
+[0.984807] BUG: unable to handle kernel NULL pointer dereference at (null)
+[0.984807] IP: [<(null)>] (null)
+...
+[0.984807][<ffffffff8143cf34>] ? cpuidle_idle_call+0xb4/0x340
+[0.984807][<ffffffff8159e7bc>] ? __atomic_notifier_call_chain+0x4c/0x70
+[0.984807][<ffffffff81001198>] ? cpu_idle+0x78/0xd0
+
+Reference:
+https://bugzilla.novell.com/show_bug.cgi?id=726296
+
+Signed-off-by: Thomas Renninger <trenn@suse.de>
+CC: Bruno Friedmann <bruno@ioda-net.ch>
+Signed-off-by: Len Brown <len.brown@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
+---
+ drivers/idle/intel_idle.c |    3 ++-
+ 1 files changed, 2 insertions(+), 1 deletions(-)
+
+diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
+index 5d2f8e1..1dafcc3 100644
+--- a/drivers/idle/intel_idle.c
++++ b/drivers/idle/intel_idle.c
+@@ -348,7 +348,8 @@ static int intel_idle_probe(void)
+        cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
+ 
+        if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
+-               !(ecx & CPUID5_ECX_INTERRUPT_BREAK))
++           !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
++           !mwait_substates)
+                        return -ENODEV;
+ 
+        pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
+-- 
+1.7.7.4
+