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| author | Lin Ming <ming.m.lin@intel.com> | 2010-01-21 09:15:20 +0800 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2010-01-22 12:30:05 -0500 |
| commit | 5f8902acf87aa206ee4b3f633104456d82747ca6 (patch) | |
| tree | 8460d04dee94605cdc448f545045598e94b0ed2a /drivers/acpi | |
| parent | a8357b0c95484b46944728712f8810d3b37bf588 (diff) | |
| download | kernel_samsung_crespo-5f8902acf87aa206ee4b3f633104456d82747ca6.zip kernel_samsung_crespo-5f8902acf87aa206ee4b3f633104456d82747ca6.tar.gz kernel_samsung_crespo-5f8902acf87aa206ee4b3f633104456d82747ca6.tar.bz2 | |
ACPICA: AcpiGetDevices: Eliminate unnecessary _STA calls
In the case where a specific _HID is requested, do not run _STA
until a _HID match is found. This eliminates potentially dozens
of _STA calls during a search for a particular device/HID.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/acpica/nsxfeval.c | 52 |
1 files changed, 33 insertions, 19 deletions
diff --git a/drivers/acpi/acpica/nsxfeval.c b/drivers/acpi/acpica/nsxfeval.c index c5a5357..ebef8a7 100644 --- a/drivers/acpi/acpica/nsxfeval.c +++ b/drivers/acpi/acpica/nsxfeval.c @@ -562,25 +562,20 @@ acpi_ns_get_device_callback(acpi_handle obj_handle, return (AE_BAD_PARAMETER); } - /* Run _STA to determine if device is present */ - - status = acpi_ut_execute_STA(node, &flags); - if (ACPI_FAILURE(status)) { - return (AE_CTRL_DEPTH); - } - - if (!(flags & ACPI_STA_DEVICE_PRESENT) && - !(flags & ACPI_STA_DEVICE_FUNCTIONING)) { - /* - * Don't examine the children of the device only when the - * device is neither present nor functional. See ACPI spec, - * description of _STA for more information. - */ - return (AE_CTRL_DEPTH); - } - - /* Filter based on device HID & CID */ - + /* + * First, filter based on the device HID and CID. + * + * 01/2010: For this case where a specific HID is requested, we don't + * want to run _STA until we have an actual HID match. Thus, we will + * not unnecessarily execute _STA on devices for which the caller + * doesn't care about. Previously, _STA was executed unconditionally + * on all devices found here. + * + * A side-effect of this change is that now we will continue to search + * for a matching HID even under device trees where the parent device + * would have returned a _STA that indicates it is not present or + * not functioning (thus aborting the search on that branch). + */ if (info->hid != NULL) { status = acpi_ut_execute_HID(node, &hid); if (status == AE_NOT_FOUND) { @@ -620,6 +615,25 @@ acpi_ns_get_device_callback(acpi_handle obj_handle, } } + /* Run _STA to determine if device is present */ + + status = acpi_ut_execute_STA(node, &flags); + if (ACPI_FAILURE(status)) { + return (AE_CTRL_DEPTH); + } + + if (!(flags & ACPI_STA_DEVICE_PRESENT) && + !(flags & ACPI_STA_DEVICE_FUNCTIONING)) { + /* + * Don't examine the children of the device only when the + * device is neither present nor functional. See ACPI spec, + * description of _STA for more information. + */ + return (AE_CTRL_DEPTH); + } + + /* We have a valid device, invoke the user function */ + status = info->user_function(obj_handle, nesting_level, info->context, return_value); return (status); |