Re: _CST Patches

Janosch Machowinski
2005-04-18T12:16:25Z

[-- Attachment #1: Type: text/plain, Size: 1270 bytes --]

> > This patch fakes an C1 state if the given states by the _CST object
> > start with anything else than C1 (like on my M6NE here it start's with
> > C2)
>
> It should not be needed. I've taken care that it work by testing
> in almost all cases by overriding the DSDT when I wrote this part to
> handle properly almost all cases (I forgot the case when C1 and C3, but
> no C2 though, that why I wrote 'almost').
>
> Normally, we register a C1 state no matter what before we check
> the content of _CST, then we just skip if a C1 type is found.
>
> If your patch is needed, then the patch I send some times ago have not been
> fully integrated in the original form, or maybe the wrong one was considered
> (the first was buggy in that regard, but the second was OK).
>
Your first patch has been modified, and now my patch is needed.
In your first implementation you did an (pr->power)++ before the loop
that started the polling of the _CST object. At the moment all C-States
are deleted (see the memset) and generated from scratch. Your idea
sounds faster to me !

> I would prefer
> memset(pr->power.states, 0, ACPI_PROCESSOR_MAX_POWER * sizeof(struct acpi_processor_cx));
> (without the loop)

I agree, looks faster to me.

A new patch is attached

Janosch

[-- Attachment #2: _CST_fakeC1.patch --]
[-- Type: text/x-patch, Size: 2081 bytes --]

--- processor_idle.original 2005-04-16 17:13:44.000000000 +0200
+++ processor_idle.c 2005-04-18 14:13:52.000000000 +0200
@@ -479,8 +479,6 @@

static int acpi_processor_get_power_info_fadt (struct acpi_processor *pr)
{
- int i;
-
ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");

if (!pr)
@@ -489,8 +487,7 @@
if (!pr->pblk)
return_VALUE(-ENODEV);

- for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
- memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
+ memset(pr->power.states, 0, ACPI_PROCESSOR_MAX_POWER * sizeof(struct acpi_processor_cx));

/* if info is obtained from pblk/fadt, type equals state */
pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
@@ -536,8 +533,8 @@
return_VALUE(-ENODEV);

pr->power.count = 0;
- for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
- memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
+
+ memset(pr->power.states, 0, ACPI_PROCESSOR_MAX_POWER * sizeof(struct acpi_processor_cx));

status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
@@ -609,6 +606,27 @@

cx.type = obj->integer.value;

+ //Test if the first entry is a C1 state, if not we fake one
+ if ((cx.type != ACPI_STATE_C1) && i == 1) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Faking C1 State"));
+ struct acpi_processor_cx c1_fake;
+ memset(&c1_fake, 0, sizeof(c1_fake));
+
+ c1_fake.address = 0;
+ c1_fake.type = ACPI_STATE_C1;
+ c1_fake.latency = 0; //How long needs a HLT instruction to execute ?
+ c1_fake.power = 0; //We don't know anything about the power consumption so we set it to 0
+ //We copy our fake C1 state over to the power states
+ (pr->power.count)++;
+ memcpy(&(pr->power.states[pr->power.count]), &c1_fake, sizeof(c1_fake));
+ //Finally we avoid to have more power states than ACPI_PROCESSOR_MAX_POWER
+ if(count == ACPI_PROCESSOR_MAX_POWER)
+ count--;
+
+ //c1_fake should be freed automaticaly
+ }
+
+
if ((cx.type != ACPI_STATE_C1) &&
(reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
continue;