Re: 2.6.16-rc5: known regressions [TP 600X S3, vanilla DSDT]

From: Sanjoy Mahajan
Date: Tue Mar 21 2006 - 02:25:40 EST

> From pervious experience, we know _THM0._TMP causes problem. If you
> fake _TMP for all THM, what could happen?

It still hangs on the second sleep. I faked them in the kernel instead
of the DSDT, by faking them in acpi_evaluate_integer() like so:

diff -r ac486e270597 -r 959c4fa10a36 drivers/acpi/utils.c
--- a/drivers/acpi/utils.c Sat Mar 18 08:35:34 2006 -0500
+++ b/drivers/acpi/utils.c Mon Mar 20 20:52:01 2006 -0500
@@ -270,7 +270,15 @@ acpi_evaluate_integer(acpi_handle handle
memset(element, 0, sizeof(union acpi_object));
buffer.length = sizeof(union acpi_object);
buffer.pointer = element;
- status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
+ if (strcmp(pathname, "_TMP") != 0)
+ status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
+ else {
+ printk(KERN_INFO PREFIX "acpi_evaluate_integer: Faking _TMP\n");
+ status = AE_OK;
+ element->type = ACPI_TYPE_INTEGER;
+ element->integer.value = 3000; /* 27 C, in deciKelvins */
+ }
if (ACPI_FAILURE(status)) {
acpi_util_eval_error(handle, pathname, status);

Each thermal zone loaded with produced printk's like "Faking _TMP", etc,
so the patch was working. It shouldn't change the result if instead I
make all the _TMP methods in the DSDT return 0xBB8 (or whatever the
magic number was).

So my plan, which I'm trying now, is to keep _TMP faked for all zones,
and take away one zone at a time until the hang goes away. If I take
away all of THM[267], then it won't hang (since THM0 by itself hangs but
THM0 without _TMP does not hang). But I hope that an earlier
combination in the search will not hang.


`A society of sheep must in time beget a government of wolves.'
- Bertrand de Jouvenal
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