Re: [Qemu-devel] [PATCH] fix acpi regression

[Wen Congyang <wency@cn.fujitsu.com>]

At 04/12/2011 04:48 PM, Isaku Yamahata Write:
> On Tue, Apr 12, 2011 at 01:13:15PM +0800, Wen Congyang wrote:
>> This bug is introduced by commit 23910d3f.
> 
> Oh, Thanks. Good catch. I agree with the first hunk.
> But what is the second hunk for? The GPE STS register is W1C.
> (NULL check and 0xff masking is okay. it's a bit redundant, though)

I found this bug when I hotplug a nic.
I do not know about ACPI.
The second hunk is the same before commit 23910d3f.
I will read ACPI spec to confirm it and update this patch.

Thanks

> 
>>From ACPI4 spec 4.7.4.1.1.
> can only be cleared by software writing a "1" to its respective bit position.
> 
> thanks,
> 
>>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>>
>> ---
>>  hw/acpi.c |   10 +++-------
>>  1 files changed, 3 insertions(+), 7 deletions(-)
>>
>> diff --git a/hw/acpi.c b/hw/acpi.c
>> index e372474..790bd3b 100644
>> --- a/hw/acpi.c
>> +++ b/hw/acpi.c
>> @@ -355,7 +355,7 @@ static uint8_t *acpi_gpe_ioport_get_ptr(ACPIGPE *gpe, uint32_t addr)
>>      if (addr < gpe->len / 2) {
>>          cur = gpe->sts + addr;
>>      } else if (addr < gpe->len) {
>> -        cur = gpe->en + addr;
>> +        cur = gpe->en + addr - gpe->len / 2;
>>      } else {
>>          abort();
>>      }
>> @@ -369,12 +369,8 @@ void acpi_gpe_ioport_writeb(ACPIGPE *gpe, uint32_t addr, uint32_t val)
>>  
>>      addr -= gpe->blk;
>>      cur = acpi_gpe_ioport_get_ptr(gpe, addr);
>> -    if (addr < gpe->len / 2) {
>> -        /* GPE_STS */
>> -        *cur = (*cur) & ~val;
>> -    } else if (addr < gpe->len) {
>> -        /* GPE_EN */
>> -        *cur = val;
>> +    if (cur != NULL) {
>> +        *cur = val & 0xff;
>>      } else {
>>          abort();
>>      }
>> -- 
>> 1.7.1
>>