summaryrefslogtreecommitdiff
path: root/include/linux/acpi.h
diff options
context:
space:
mode:
authorLan Tianyu <tianyu.lan@intel.com>2014-11-23 16:22:54 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-11-24 03:04:55 +0300
commit40e7fcb19293cbdff02c74cb0668413480f82ea1 (patch)
tree05e1c91e4f3b06bf4234d0ac1014acdf4757766b /include/linux/acpi.h
parent5d01410fe4d92081f349b013a2e7a95429e4f2c9 (diff)
downloadlinux-40e7fcb19293cbdff02c74cb0668413480f82ea1.tar.xz
ACPI: Add _DEP support to fix battery issue on Asus T100TA
ACPI 5.0 introduces _DEP (Operation Region Dependencies) to designate device objects that OSPM should assign a higher priority in start ordering due to future operation region accesses. On Asus T100TA, ACPI battery info are read from a I2C slave device via I2C operation region. Before I2C operation region handler is installed, battery _STA always returns 0. There is a _DEP method of designating start order under battery device node. This patch is to implement _DEP feature to fix battery issue on the Asus T100TA. Introducing acpi_dep_list and adding dep_unmet count in struct acpi_device. During ACPI namespace scan, create struct acpi_dep_data for a valid pair of master (device pointed to by _DEP)/ slave(device with _DEP), record master's and slave's ACPI handle in it and put it into acpi_dep_list. The dep_unmet count will increase by one if there is a device under its _DEP. Driver's probe() should return EPROBE_DEFER when find dep_unmet is larger than 0. When I2C operation region handler is installed, remove all struct acpi_dep_data on the acpi_dep_list whose master is pointed to I2C host controller and decrease slave's dep_unmet. When dep_unmet decreases to 0, all _DEP conditions are met and then do acpi_bus_attach() for the device in order to resolve battery _STA issue on the Asus T100TA. Link: https://bugzilla.kernel.org/show_bug.cgi?id=69011 Tested-by: Jan-Michael Brummer <jan.brummer@tabos.org> Tested-by: Adam Williamson <adamw@happyassassin.net> Tested-by: Michael Shigorin <shigorin@gmail.com> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/linux/acpi.h')
-rw-r--r--include/linux/acpi.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 407a12f663eb..6cb310388c88 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -431,6 +431,7 @@ static inline bool acpi_driver_match_device(struct device *dev,
int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
int acpi_device_modalias(struct device *, char *, int);
+void acpi_walk_dep_device_list(acpi_handle handle);
struct platform_device *acpi_create_platform_device(struct acpi_device *);
#define ACPI_PTR(_ptr) (_ptr)