Messages in this thread Patch in this message | | | Date | Wed, 09 Sep 2009 23:17:04 +0200 | From | Knut Petersen <> | Subject | [PATCH] Fix Aopen i915GMm-hfs hwmon support |
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Hi Linus!
Hwmon support is broken for the Aopen i915GMm-hfs. The reason is the default value ENFORCE_RESOURCES_STRICT for acpi_enforce_resources in drivers/acpi/osl.c.
The use of ENFORCE_RESOURCES_LAX is proven to be ok by more than 30000 hours of uptime on my i915GMm-hfs.
Of course, it would be possible to tell all users of that board to add a cmdline parameter to restore hwmon support, but I believe that it is a good idea to do things automatically that can be done that way. And we should only break things if it is really necessary.
The attached trivial patch looks for the i915GMm-hfs board during init and changes the default to lax ACPI resource checking only for that board. I think this is reasonable, and probably a number of other boards could also be handled that way.
There is a high probability that for lots of people 2.6.31 will be their first kernel using strict resource enforcement, as 2.6.31 will be used by a number of distributions.
Because of that I believe this patch should be included in kernel 2.6.31.
cu, Knut --- linux-2.6.31-rc9-git3/drivers/acpi/osl.c 2009-09-06 01:38:12.000000000 +0200 +++ linux-2.6.31-rc9-git3-kp/drivers/acpi/osl.c 2009-09-09 18:41:51.000000000 +0200 @@ -1113,6 +1113,8 @@ * - no (0) * -> ACPI Operation Region resources will not be registered * + * We do detect some special boards and switch to lax checking + * as we do not want to break support of sensors. */ #define ENFORCE_RESOURCES_STRICT 2 #define ENFORCE_RESOURCES_LAX 1 @@ -1120,8 +1122,30 @@ static unsigned int acpi_enforce_resources = ENFORCE_RESOURCES_STRICT; +static int enforce_resources_lax(const struct dmi_system_id *d) +{ + + printk(KERN_NOTICE "ACPI: %s detected: " + "using lax resource checking\n", d->ident); + acpi_enforce_resources = ENFORCE_RESOURCES_LAX; + return 0; +} + +static struct dmi_system_id osl_dmi_table[] __initdata = { + { + .callback = enforce_resources_lax, + .ident = "AOpen i915GMm-HFS", + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"), + DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"), + }, + }, + {} +}; + static int __init acpi_enforce_resources_setup(char *str) { + if (str == NULL || *str == '\0') return 0; @@ -1421,3 +1445,11 @@ } #endif + +static int __init acpi_osl_init(void) +{ + dmi_check_system(osl_dmi_table); + return 0; +} + +module_init(acpi_osl_init); | |