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authorLv Zheng <lv.zheng@intel.com>2016-09-13 17:48:27 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-09-17 01:10:43 +0200
commit307ecb0aa3a24528efd1cfcea8215b2d82df6e10 (patch)
tree0f60262d00305de3163cd9fda66b9b01369bb412 /drivers/acpi
parent237502055915b7bb6c04f4eafd85f3a4704771fb (diff)
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ACPI / sysfs: Fix an issue for LoadTable opcode
OEM tables can be installed via RSDT/XSDT, in this case, they have already been created under /sys/firmware/acpi/tables. For this kind of tables, normally LoadTable opcode will be executed to load them. If LoadTable opcode is executed after acpi_sysfs_init(), acpi_sysfs_table_handler() will be invoked, thus a redundant table file will be created under /sys/firmware/acpi/tables/dynamic. Then running "acpidump" on such platform results in an error, complaining blank empty table (see Link 1 below). The bug can be reproduced by customizing an OEM1 table, allowing it to be overridden via 'table_sigs' (drivers/acpi/tables.c), adding the following code to the customized DSDT to load it: Name (OEMH, Zero) Name (OEMF, One) If (LEqual (OEMF, One)) { Store (LoadTable ("OEM1", "Intel", "Test"), OEMH) Store (Zero, OEMF) } In order to make sure that the OEM1 table is installed after acpi_sysfs_init(), acpi_sysfs_init() can be moved before invoking acpi_load_tables(). Then the following command execution result can be seen: # acpidump > acpidump.txt Could not read table header: /sysfs/firmware/acpi/tables/dynamic/OEM12 Could not get ACPI table at index 17, AE_BAD_HEADER Link: https://bugzilla.kernel.org/show_bug.cgi?id=150841 # [1] Link: https://github.com/acpica/acpica/commit/ed6a5fbc Reported-by: Jason Voelz <jason.voelz@intel.com> Reported-by: Francisco Leoner <francisco.j.lenoer.soto@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/sysfs.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index 703c993888b2..c88d4bdf2165 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -383,7 +383,7 @@ acpi_status acpi_sysfs_table_handler(u32 event, void *table, void *context)
struct acpi_table_attr *table_attr;
switch (event) {
- case ACPI_TABLE_EVENT_LOAD:
+ case ACPI_TABLE_EVENT_INSTALL:
table_attr =
kzalloc(sizeof(struct acpi_table_attr), GFP_KERNEL);
if (!table_attr)
@@ -397,7 +397,9 @@ acpi_status acpi_sysfs_table_handler(u32 event, void *table, void *context)
} else
list_add_tail(&table_attr->node, &acpi_table_attr_list);
break;
+ case ACPI_TABLE_EVENT_LOAD:
case ACPI_TABLE_EVENT_UNLOAD:
+ case ACPI_TABLE_EVENT_UNINSTALL:
/*
* we do not need to do anything right now
* because the table is not deleted from the
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