Hi Linus, A single fix for HyperV -- we never NEED the legacy PIC on HyperV, and in kexec/kdump scenarios we don't always know that we originally booted EFI. The right answer is probably to augment the legacy PIC initialization code to detect a not-present PIC, but that is way too high risk for right now. The following changes since commit ca3ba2a2f4a49a308e7d78c784d51b2332064f15: x86, hyperv: Bypass the timer_irq_works() check (2014-03-27 11:02:45 -0700) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-hyperv-for-linus for you to fetch changes up to 8df28b82ff0649dd293f0469b97792cfb9ed10ab: x86, hyperv: When on Hyper-v use NULL legacy PIC (2014-04-03 22:00:13 -0700) ---------------------------------------------------------------- K. Y. Srinivasan (1): x86, hyperv: When on Hyper-v use NULL legacy PIC arch/x86/kernel/cpu/mshyperv.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 832d05a914ba..b7d82c7e1257 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -93,14 +93,8 @@ static void __init ms_hyperv_init_platform(void) printk(KERN_INFO "HyperV: LAPIC Timer Frequency: %#x\n", lapic_timer_frequency); - /* - * On Hyper-V, when we are booting off an EFI firmware stack, - * we do not have many legacy devices including PIC, PIT etc. - */ - if (efi_enabled(EFI_BOOT)) { - printk(KERN_INFO "HyperV: Using null_legacy_pic\n"); - legacy_pic = &null_legacy_pic; - } + printk(KERN_INFO "HyperV: Using null_legacy_pic\n"); + legacy_pic = &null_legacy_pic; } #endif -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html