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Re: [Qemu-devel] [PATCH] fix acpi regression
From: |
Wen Congyang |
Subject: |
Re: [Qemu-devel] [PATCH] fix acpi regression |
Date: |
Tue, 12 Apr 2011 17:26:12 +0800 |
User-agent: |
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 |
At 04/12/2011 05:20 PM, Isaku Yamahata Write:
> On Tue, Apr 12, 2011 at 05:08:18PM +0800, Wen Congyang wrote:
>> 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.
>
> You mean gpe_writeb(), gpe_write_val(), gpe_reset_val()?
> gpe_reset_val() does W1C.
> The GPE0_LEN of piix4 is 4 byte length and the first 2 registers are
> sts register. From the old code,
>
> static void gpe_reset_val(uint16_t *cur, int addr, uint32_t val)
> {
> uint16_t x1, x0 = val & 0xff;
> int shift = (addr & 1) ? 8 : 0;
>
> x1 = (*cur >> shift) & 0xff;
>
> x1 = x1 & ~x0; <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< W1C
>
> *cur = (*cur & (0xff << (8 - shift))) | (x1 << shift);
> }
>
>
> static void gpe_writeb(void *opaque, uint32_t addr, uint32_t val)
> {
> PIIX4PMState *s = opaque;
> struct gpe_regs *g = &s->gpe;
>
> switch (addr) {
> case GPE_BASE:
> case GPE_BASE + 1:
> gpe_reset_val(&g->sts, addr, val);
> break;
Ah, you are right.
Thanks.
>
> thanks,
>
>>
>> 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 <address@hidden>
>>>>
>>>> ---
>>>> 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
>>>>
>>
>>
>