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Some PIIX4 chipsets need to be told to generate Stop Breaks by setting

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the appropriate bit in the DEVACTB register.
This change allows the C2 state on those systems to work as expected.

Reviewed by:	njl
Submitted by:	Andriy Gapon <avg at icyb.net.ua>
MFC after:	1 week
This commit is contained in:
Rui Paulo 2008-03-09 11:19:03 +00:00
parent 395adfbe34
commit 8a000acaa9
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=176972
1 changed files with 20 additions and 0 deletions
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20
sys/dev/acpica/acpi_cpu.c
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@ -113,6 +113,12 @@ struct acpi_cpu_device {
#define PCI_REVISION_B_STEP 1
#define PCI_REVISION_4E 2
#define PCI_REVISION_4M 3
#define PIIX4_DEVACTB_REG 0x58
#define PIIX4_BRLD_EN_IRQ0 (1<<0)
#define PIIX4_BRLD_EN_IRQ (1<<1)
#define PIIX4_BRLD_EN_IRQ8 (1<<5)
#define PIIX4_STOP_BREAK_MASK (PIIX4_BRLD_EN_IRQ0 | PIIX4_BRLD_EN_IRQ | PIIX4_BRLD_EN_IRQ8)
#define PIIX4_PCNTRL_BST_EN (1<<10)
/* Platform hardware resource information. */
static uint32_t cpu_smi_cmd; /* Value to write to SMI_CMD. */
@ -1004,6 +1010,7 @@ static int
acpi_cpu_quirks(void)
{
device_t acpi_dev;
uint32_t val;
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
@ -1052,12 +1059,25 @@ acpi_cpu_quirks(void)
* See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
* Livelock") from the January 2002 PIIX4 specification update.
* Applies to all PIIX4 models.
*
* Also, make sure that all interrupts cause a "Stop Break"
* event to exit from C2 state.
*/
case PCI_REVISION_A_STEP:
case PCI_REVISION_B_STEP:
case PCI_REVISION_4E:
case PCI_REVISION_4M:
cpu_quirks |= CPU_QUIRK_NO_C3;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"acpi_cpu: working around PIIX4 bug, disabling C3\n"));
val = pci_read_config(acpi_dev, PIIX4_DEVACTB_REG, 4);
if ((val & PIIX4_STOP_BREAK_MASK) != PIIX4_STOP_BREAK_MASK) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"PIIX4: enabling IRQs to generate Stop Break\n"));
val |= PIIX4_STOP_BREAK_MASK;
pci_write_config(acpi_dev, PIIX4_DEVACTB_REG, val, 4);
}
break;
default:
break;