[SeaBIOS] [PATCH v3 1/5] hw/i386: allow SHPC for Q35 machine

[Marcel Apfelbaum]

On 03/08/2017 15:52, Michael S. Tsirkin wrote:
> On Sat, Jul 29, 2017 at 02:37:49AM +0300, Aleksandr Bezzubikov wrote:
>> Unmask previously masked SHPC feature in _OSC method.
>>
>> Signed-off-by: Aleksandr Bezzubikov <zuban32s at gmail.com>
> 

Hi Michael,


> This does not do what the subject says - it enables
> SHPC unconditionally. And I think it will actually break
> ACPI hotplug for the PC unless we add an interface to
> disable ACPI hotplug and enable SHPC.
> 
> Pls limit to Q35 only.
>

The code is inside build_q35_osc_method,
I don't understand how it affects the PC machine.

Thanks,
Marcel


>> ---
>>   hw/i386/acpi-build.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
>> index 6b7bade..2ab32f9 100644
>> --- a/hw/i386/acpi-build.c
>> +++ b/hw/i386/acpi-build.c
>> @@ -1848,9 +1848,9 @@ static Aml *build_q35_osc_method(void)
>>   
>>       /*
>>        * Always allow native PME, AER (no dependencies)
>> -     * Never allow SHPC (no SHPC controller in this system)
>> +     * Allow SHPC (PCI bridges can have SHPC controller)
>>        */
>> -    aml_append(if_ctx, aml_and(a_ctrl, aml_int(0x1D), a_ctrl));
>> +    aml_append(if_ctx, aml_and(a_ctrl, aml_int(0x1F), a_ctrl));
>>   
>>       if_ctx2 = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(1))));
>>       /* Unknown revision */
>> -- 
>> 2.7.4