From: Benjamin Herrenschmidt This is a resend of a patch sent in July and that got lost somewhat, the "VSCR" register wasn't restored properly from the context on load_up_altivec (typo), please apply the fix: Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Andrew Morton --- 25-akpm/arch/ppc64/kernel/head.S | 1 + 1 files changed, 1 insertion(+) diff -puN arch/ppc64/kernel/head.S~ppc64fix-missing-register-in-altivec-context-switch arch/ppc64/kernel/head.S --- 25/arch/ppc64/kernel/head.S~ppc64fix-missing-register-in-altivec-context-switch 2004-09-12 23:01:43.010635136 -0700 +++ 25-akpm/arch/ppc64/kernel/head.S 2004-09-12 23:01:43.023633160 -0700 @@ -1579,6 +1579,7 @@ _STATIC(load_up_altivec) li r10,THREAD_VSCR stw r4,THREAD_USED_VR(r5) lvx vr0,r10,r5 + mtvscr vr0 REST_32VRS(0,r4,r5) #ifndef CONFIG_SMP /* Update last_task_used_math to 'current' */ _