Luca Tettamanti wrote:
Il Sun, Jan 11, 2009 at 08:04:56PM +0100, Hans de Goede ha scritto:
Luca Tettamanti wrote:
On Thu, Jan 8, 2009 at 5:15 PM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
[...]
So back to the discussion about changing the default of
acpi_enforce_resources to strict, Jean and I have been discussing this on
IRC and we feel it will most likely cause too much pain. So we would like to
suggest to make the default depend up on the motherboard. Our plan is to
have the default be "auto" and that will mean "lax", unless the motherboard
is atk0110 (Asus ACPI interface for reading hwmon data) capable and in that
case "auto" will mean "strict"
Hum, that would mean putting ATK specific code into ACPI subsystem.
It's not pretty :S
Agreed, an alternative Jean and I discussed was to make the default
strict for all Asus boards, that would be easier (simple strcmp on
baseboard manufacturer). I don't know how large the atk detection code
is.
Pretty small, 25 LoC.
<snip>
Detection is pretty easy, the only problem is that I had to hijack the
fs_initcal level, because the code shall run _after_ the interpreter has
been initialized (subsys) but before native drivers have a chance to
poke the HW. So this what I've come up with (I just wrote it - I plan to
reboot tomorrow to test it...):
Looks good to me, Len would something like this be acceptable?
Regards,
Hans
---
Documentation/kernel-parameters.txt | 19 +++++++++++++
drivers/acpi/osl.c | 49 ++++++++++++++++++++++++++++++++++--
2 files changed, 66 insertions(+), 2 deletions(-)
Index: linux-2.6.git/Documentation/kernel-parameters.txt
===================================================================
--- linux-2.6.git.orig/Documentation/kernel-parameters.txt 2009-01-12 21:21:34.573074955 +0100
+++ linux-2.6.git/Documentation/kernel-parameters.txt 2009-01-12 21:22:01.164076567 +0100
@@ -251,6 +251,25 @@
to assume that this machine's pmtimer latches its value
and always returns good values.
+ acpi_enforce_resources= [ACPI]
+ { strict, auto, lax, no }
+ Check for resource conflicts between native drivers
+ and ACPI OperationRegions (SystemIO and System Memory
+ only). IO ports and memory declared in ACPI might be
+ used by the ACPI subsystem in arbitrary AML code and
+ can interfere with legacy drivers.
+ strict: access to resources claimed by ACPI is denied;
+ legacy drivers trying to access reserved resources
+ will fail to load.
+ auto (default): try and detect ACPI devices with known
+ ACPI drivers; escalates the setting to "strict" if such
+ a device is found, otherwise behaves like "lax".
+ lax: access to resources claimed by ACPI is allowed;
+ legacy drivers trying to access reserved resources
+ will load and a warning message is logged.
+ no: ACPI OperationRegions are not marked as reserved,
+ no further checks are performed.
+
agp= [AGP]
{ off | try_unsupported }
off: disable AGP support
Index: linux-2.6.git/drivers/acpi/osl.c
===================================================================
--- linux-2.6.git.orig/drivers/acpi/osl.c 2009-01-12 21:21:34.549076302 +0100
+++ linux-2.6.git/drivers/acpi/osl.c 2009-01-12 21:22:01.164076567 +0100
@@ -1063,6 +1063,9 @@
* in arbitrary AML code and can interfere with legacy drivers.
* acpi_enforce_resources= can be set to:
*
+ * - auto (3)
+ * -> detect possible conflicts with ACPI drivers and switch to
+ * strict if needed, otherwise act like lax
* - strict (2)
* -> further driver trying to access the resources will not load
* - lax (default) (1)
@@ -1073,11 +1076,12 @@
* -> ACPI Operation Region resources will not be registered
*
*/
-#define ENFORCE_RESOURCES_STRICT 2
+#define ENFORCE_RESOURCES_STRICT 3
+#define ENFORCE_RESOURCES_AUTO 2
#define ENFORCE_RESOURCES_LAX 1
#define ENFORCE_RESOURCES_NO 0
-static unsigned int acpi_enforce_resources = ENFORCE_RESOURCES_LAX;
+static unsigned int acpi_enforce_resources = ENFORCE_RESOURCES_AUTO;
static int __init acpi_enforce_resources_setup(char *str)
{
@@ -1086,6 +1090,8 @@
if (!strcmp("strict", str))
acpi_enforce_resources = ENFORCE_RESOURCES_STRICT;
+ else if (!strcmp("auto", str))
+ acpi_enforce_resources = ENFORCE_RESOURCES_AUTO;
else if (!strcmp("lax", str))
acpi_enforce_resources = ENFORCE_RESOURCES_LAX;
else if (!strcmp("no", str))
@@ -1096,6 +1102,40 @@
__setup("acpi_enforce_resources=", acpi_enforce_resources_setup);
+static int __init acpi_detect_asus_atk(void)
+{
+ struct acpi_buffer output;
+ union acpi_object *hid;
+ acpi_status ret;
+
+ if (acpi_enforce_resources != ENFORCE_RESOURCES_AUTO)
+ return 0;
+
+ output.pointer = NULL;
+ output.length = ACPI_ALLOCATE_BUFFER;
+ ret = acpi_evaluate_object_typed(NULL, "\\_SB.PCI0.SBRG.ASOC._HID",
+ NULL, &output, ACPI_TYPE_STRING);
+ if (ret == AE_OK) {
+ hid = output.pointer;
+
+ if (!strcmp("ATK0110", hid->string.pointer)) {
+ printk(KERN_DEBUG "Asus ATK0110 interface detected: "
+ "enforcing resource checking.\n");
+
+ acpi_enforce_resources = ENFORCE_RESOURCES_STRICT;
+ } else {
+ acpi_enforce_resources = ENFORCE_RESOURCES_LAX;
+ }
+
+ ACPI_FREE(output.pointer);
+ } else {
+ acpi_enforce_resources = ENFORCE_RESOURCES_LAX;
+ }
+
+ return 0;
+}
+fs_initcall(acpi_detect_asus_atk);
+
/* Check for resource conflicts between ACPI OperationRegions and native
* drivers */
int acpi_check_resource_conflict(struct resource *res)
Luca
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
