On 2015/3/4 13:31, Ingo Molnar wrote: > > * Li, Aubrey <aubrey...@linux.intel.com> wrote: > >> On 2015/3/4 13:08, Ingo Molnar wrote: >>> >>> * Li, Aubrey <aubrey...@linux.intel.com> wrote: >>> >>>> On ACPI hardware reduced platform, the legacy PIC and PIT may not be >>>> initialized even though they may be present in silicon. Touching >>>> these legacy components causes unexpected result on system. >>>> >>>> On Bay Trail-T(ASUS-T100) platform, touching these legacy components >>>> blocks platform hardware low idle power state(S0ix) during system suspend. >>>> So we should bypass them on ACPI hardware reduced platform. >>>> >>>> Suggested-by: Arjan van de Ven <ar...@linux.intel.com> >>>> Signed-off-by: Li Aubrey <aubrey...@linux.intel.com> >>>> Cc: Len Brown <len.br...@intel.com> >>>> Cc: Rafael J. Wysocki <rafael.j.wyso...@intel.com> >>>> --- >>>> arch/x86/kernel/irqinit.c | 6 +++++- >>>> arch/x86/kernel/time.c | 3 ++- >>>> 2 files changed, 7 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c >>>> index 70e181e..9a64cc3 100644 >>>> --- a/arch/x86/kernel/irqinit.c >>>> +++ b/arch/x86/kernel/irqinit.c >>>> @@ -75,7 +75,11 @@ void __init init_ISA_irqs(void) >>>> #if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC) >>>> init_bsp_APIC(); >>>> #endif >>>> - legacy_pic->init(0); >>>> + if (acpi_gbl_reduced_hardware) { >>>> + pr_info("Using NULL legacy PIC\n"); >>>> + legacy_pic = &null_legacy_pic; >>>> + } else >>>> + legacy_pic->init(0); >>>> >>>> for (i = 0; i < nr_legacy_irqs(); i++) >>>> irq_set_chip_and_handler(i, chip, handle_level_irq); >>>> diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c >>>> index 25adc0e..5ba94fa 100644 >>>> --- a/arch/x86/kernel/time.c >>>> +++ b/arch/x86/kernel/time.c >>>> @@ -14,6 +14,7 @@ >>>> #include <linux/i8253.h> >>>> #include <linux/time.h> >>>> #include <linux/export.h> >>>> +#include <linux/acpi.h> >>>> >>>> #include <asm/vsyscall.h> >>>> #include <asm/x86_init.h> >>>> @@ -76,7 +77,7 @@ void __init setup_default_timer_irq(void) >>>> /* Default timer init function */ >>>> void __init hpet_time_init(void) >>>> { >>>> - if (!hpet_enable()) >>>> + if (!hpet_enable() && !acpi_gbl_reduced_hardware) >>>> setup_pit_timer(); >>>> setup_default_timer_irq(); >>>> } >>> >>> So the whole acpi_gbl_reduced_hardware flaggery sucks as it mixes >>> various hardware drivers that have little relation to each other... >>> >>> Instead of having a proper platform init this flag hooks into various >>> drivers and generic code, such as the efi reboot and shutdown code, >>> and now the generic irq init code. >>> >>> For this IRQ init problem, why not add a proper callback to >>> x86_platform_ops, define your own IRQ init function, initialize it in >>> your platform init sequence and let it be called? That solves it >>> without creating an ugly mix of different platform methods. >>> >>> For the EFI shutdown case, what's wrong with setting your own >>> pm_power_off handler like most of the other platforms are doing? Plus >>> the EFI code in drivers/firmware/efi/reboot.c should probably only set >>> the shutdown handler if pm_power_off is still NULL. >> >> I think our goal is to make the code as generic as possible for all >> x86 platform, rather than creating a new x86 branch, I added Alan >> Cox for this strategy discussion. >> >> Do you have any inputs for the patch itself? > > Other than that the patch is unacceptable for an upstream merge in its > current form for the reason I mentioned? No.
So you are suggesting we extend a new x86 platform branch and override the x86_platform and pm_power_off and reboot, like what intel_mid does? Thanks, -Aubrey > > Thanks, > > Ingo > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/