diff options
Diffstat (limited to 'drivers/acpi/utilities/utmisc.c')
| -rw-r--r-- | drivers/acpi/utilities/utmisc.c | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/drivers/acpi/utilities/utmisc.c b/drivers/acpi/utilities/utmisc.c index 2a9110c06391..89efba7bf449 100644 --- a/drivers/acpi/utilities/utmisc.c +++ b/drivers/acpi/utilities/utmisc.c @@ -63,6 +63,7 @@ ACPI_MODULE_NAME("utmisc") acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id) { acpi_native_uint i; + acpi_native_uint j; acpi_status status; ACPI_FUNCTION_TRACE("ut_allocate_owner_id"); @@ -82,29 +83,46 @@ acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id) return_ACPI_STATUS(status); } - /* Find a free owner ID */ + /* + * Find a free owner ID, cycle through all possible IDs on repeated + * allocations. Note: Index for next possible ID is equal to the value + * of the last allocated ID. + */ + for (i = 0, j = acpi_gbl_last_owner_id; i < 32; i++, j++) { + if (j >= 32) { + j = 0; /* Wraparound to ID start */ + } + + if (!(acpi_gbl_owner_id_mask & (1 << j))) { + /* + * Found a free ID. The actual ID is the bit index plus one, + * making zero an invalid Owner ID. Save this as the last ID + * allocated and update the global ID mask. + */ + acpi_gbl_last_owner_id = (acpi_owner_id) (j + 1); + *owner_id = acpi_gbl_last_owner_id; - for (i = 0; i < 32; i++) { - if (!(acpi_gbl_owner_id_mask & (1 << i))) { ACPI_DEBUG_PRINT((ACPI_DB_VALUES, "Current owner_id mask: %8.8X New ID: %2.2X\n", acpi_gbl_owner_id_mask, - (unsigned int)(i + 1))); + (unsigned int) + acpi_gbl_last_owner_id)); - acpi_gbl_owner_id_mask |= (1 << i); - *owner_id = (acpi_owner_id) (i + 1); + acpi_gbl_owner_id_mask |= (1 << j); goto exit; } } /* - * If we are here, all owner_ids have been allocated. This probably should + * All owner_ids have been allocated. This typically should * not happen since the IDs are reused after deallocation. The IDs are * allocated upon table load (one per table) and method execution, and * they are released when a table is unloaded or a method completes * execution. + * + * If this error happens, there may be very deep nesting of invoked control + * methods, or there may be a bug where the IDs are not released. */ - *owner_id = 0; status = AE_OWNER_ID_LIMIT; ACPI_REPORT_ERROR(("Could not allocate new owner_id (32 max), AE_OWNER_ID_LIMIT\n")); |