Commit 5f8902acf87aa206ee4b3f633104456d82747ca6
Committed by
Len Brown
Len Brown
1 parent
a8357b0c95
Exists in
master
and in
7 other branches
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>
Showing 1 changed file with 33 additions and 19 deletions Side-by-side Diff
drivers/acpi/acpica/nsxfeval.c
| ... | ... | @@ -562,25 +562,20 @@ |
| 562 | 562 | return (AE_BAD_PARAMETER); |
| 563 | 563 | } |
| 564 | 564 | |
| 565 | - /* Run _STA to determine if device is present */ | |
| 566 | - | |
| 567 | - status = acpi_ut_execute_STA(node, &flags); | |
| 568 | - if (ACPI_FAILURE(status)) { | |
| 569 | - return (AE_CTRL_DEPTH); | |
| 570 | - } | |
| 571 | - | |
| 572 | - if (!(flags & ACPI_STA_DEVICE_PRESENT) && | |
| 573 | - !(flags & ACPI_STA_DEVICE_FUNCTIONING)) { | |
| 574 | - /* | |
| 575 | - * Don't examine the children of the device only when the | |
| 576 | - * device is neither present nor functional. See ACPI spec, | |
| 577 | - * description of _STA for more information. | |
| 578 | - */ | |
| 579 | - return (AE_CTRL_DEPTH); | |
| 580 | - } | |
| 581 | - | |
| 582 | - /* Filter based on device HID & CID */ | |
| 583 | - | |
| 565 | + /* | |
| 566 | + * First, filter based on the device HID and CID. | |
| 567 | + * | |
| 568 | + * 01/2010: For this case where a specific HID is requested, we don't | |
| 569 | + * want to run _STA until we have an actual HID match. Thus, we will | |
| 570 | + * not unnecessarily execute _STA on devices for which the caller | |
| 571 | + * doesn't care about. Previously, _STA was executed unconditionally | |
| 572 | + * on all devices found here. | |
| 573 | + * | |
| 574 | + * A side-effect of this change is that now we will continue to search | |
| 575 | + * for a matching HID even under device trees where the parent device | |
| 576 | + * would have returned a _STA that indicates it is not present or | |
| 577 | + * not functioning (thus aborting the search on that branch). | |
| 578 | + */ | |
| 584 | 579 | if (info->hid != NULL) { |
| 585 | 580 | status = acpi_ut_execute_HID(node, &hid); |
| 586 | 581 | if (status == AE_NOT_FOUND) { |
| ... | ... | @@ -619,6 +614,25 @@ |
| 619 | 614 | return (AE_OK); |
| 620 | 615 | } |
| 621 | 616 | } |
| 617 | + | |
| 618 | + /* Run _STA to determine if device is present */ | |
| 619 | + | |
| 620 | + status = acpi_ut_execute_STA(node, &flags); | |
| 621 | + if (ACPI_FAILURE(status)) { | |
| 622 | + return (AE_CTRL_DEPTH); | |
| 623 | + } | |
| 624 | + | |
| 625 | + if (!(flags & ACPI_STA_DEVICE_PRESENT) && | |
| 626 | + !(flags & ACPI_STA_DEVICE_FUNCTIONING)) { | |
| 627 | + /* | |
| 628 | + * Don't examine the children of the device only when the | |
| 629 | + * device is neither present nor functional. See ACPI spec, | |
| 630 | + * description of _STA for more information. | |
| 631 | + */ | |
| 632 | + return (AE_CTRL_DEPTH); | |
| 633 | + } | |
| 634 | + | |
| 635 | + /* We have a valid device, invoke the user function */ | |
| 622 | 636 | |
| 623 | 637 | status = info->user_function(obj_handle, nesting_level, info->context, |
| 624 | 638 | return_value); |