From 8ea98655775e904ea406d74a887d0b2254651b5a Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Wed, 1 Jul 2015 14:44:31 +0800 Subject: [PATCH] ACPICA: Namespace: Change namespace override to avoid node deletion ACPICA commit c0ce529e1fbb8ec47d2522a3aa10f3ab77e16e41 There is no reference counting implemented for struct acpi_namespace_node, so it is currently not removable during runtime. This patch changes the namespace override code to keep the old struct acpi_namespace_node undeleted so that the override mechanism can happen during runtime. Bob Moore. Link: https://github.com/acpica/acpica/commit/c0ce529e Signed-off-by: Lv Zheng Signed-off-by: Bob Moore Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpica/nssearch.c | 23 +++++++++++++++++++---- include/acpi/acpixf.h | 5 +++++ 2 files changed, 24 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/acpica/nssearch.c b/drivers/acpi/acpica/nssearch.c index 47fbe5b33524..d73904013830 100644 --- a/drivers/acpi/acpica/nssearch.c +++ b/drivers/acpi/acpica/nssearch.c @@ -331,13 +331,28 @@ acpi_ns_search_and_enter(u32 target_name, /* * If the namespace override feature is enabled for this node, - * delete any existing node. This can only happen during the - * boot stage, thus it is safe to remove the node here. + * delete any existing attached sub-object and make the node + * look like a new node that is owned by the override table. */ if (flags & ACPI_NS_OVERRIDE_IF_FOUND) { + ACPI_DEBUG_PRINT((ACPI_DB_NAMES, + "Namespace override: %4.4s pass %u type %X Owner %X\n", + ACPI_CAST_PTR(char, + &target_name), + interpreter_mode, + (*return_node)->type, + walk_state->owner_id)); + acpi_ns_delete_children(*return_node); - acpi_ns_remove_node(*return_node); - *return_node = ACPI_ENTRY_NOT_FOUND; + if (acpi_gbl_runtime_namespace_override) { + acpi_ut_remove_reference((*return_node)->object); + (*return_node)->object = NULL; + (*return_node)->owner_id = + walk_state->owner_id; + } else { + acpi_ns_remove_node(*return_node); + *return_node = ACPI_ENTRY_NOT_FOUND; + } } /* Return an error if we don't expect to find the object */ diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h index 213ed7ecfd8d..f6d807170346 100644 --- a/include/acpi/acpixf.h +++ b/include/acpi/acpixf.h @@ -228,6 +228,11 @@ ACPI_INIT_GLOBAL(u8, acpi_gbl_disable_auto_repair, FALSE); */ ACPI_INIT_GLOBAL(u8, acpi_gbl_disable_ssdt_table_install, FALSE); +/* + * Optionally enable runtime namespace override. + */ +ACPI_INIT_GLOBAL(u8, acpi_gbl_runtime_namespace_override, TRUE); + /* * We keep track of the latest version of Windows that has been requested by * the BIOS. ACPI 5.0.