battery: Add the battery hooking API
Subsystems (3)
PATCH v12 1/4 battery: Add the battery hooking API
This is a patch that implements a generic hooking API for the generic ACPI battery driver.
With this new generic API, drivers can expose platform specific behaviour via sysfs attributes in /sys/class/power_supply/BATn/ in a generic way.
A perfect example of the need for this API are Lenovo ThinkPads.
Lenovo ThinkPads have a ACPI extension that allows the setting of start and stop charge thresholds in the EC and battery firmware via ACPI. The thinkpad_acpi module can use this API to expose sysfs attributes that it controls inside the ACPI battery driver sysfs tree, under /sys/class/power_supply/BATN/.
The file drivers/acpi/battery.h has been moved to include/acpi/battery.h and the includes inside ac.c, sbs.c, and battery.c have been adjusted to reflect that.
When drivers hooks into the API, the API calls add_battery() for each battery in the system that passes it a acpi_battery struct. Then, the drivers can use device_create_file() to create new sysfs attributes with that struct and identify the batteries for per-battery attributes.
---
Notes:
v7:
* Implemented mutual exclusion for hooking methods and battery callbacks
* Fixed a BUG where errors in other modules would occur when the modules that depend on battery get unloaded
v8:
* Use list_for_each_safe instead of list_for_each for the module exit function where deletion of nodes occurs
v9:
* No changes in this patch in v9
v10:
* Fix compiler warnings in Intel's 0-day CI
v11:
* Fix changelog formatting
* Make lists and mutex static
v12:
* Change all applicable list_for_each to list_for_each_entry
* Define pr_fmt to include module name for pr_*
drivers/acpi/ac.c | 2 +- drivers/acpi/battery.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++- drivers/acpi/battery.h | 11 ---- drivers/acpi/sbs.c | 2 +- include/acpi/battery.h | 21 +++++++ 5 files changed, 171 insertions(+), 16 deletions(-) delete mode 100644 drivers/acpi/battery.h create mode 100644 include/acpi/battery.h
drivers/acpi/ac.c +1 -1
@@ -33,7 +33,7 @@#include <linux/platform_device.h> #include <linux/power_supply.h> #include <linux/acpi.h> -#include "battery.h" +#include <acpi/battery.h> #define PREFIX "ACPI: "
drivers/acpi/battery.c +148 -3
196 lines not on this page · raw message
drivers/acpi/battery.h deleted +0 -11
@@ -1,11 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef __ACPI_BATTERY_H -#define __ACPI_BATTERY_H - -#define ACPI_BATTERY_CLASS "battery" - -#define ACPI_BATTERY_NOTIFY_STATUS 0x80 -#define ACPI_BATTERY_NOTIFY_INFO 0x81 -#define ACPI_BATTERY_NOTIFY_THRESHOLD 0x82 - -#endif
drivers/acpi/sbs.c +1 -1
@@ -32,9 +32,9 @@#include <linux/delay.h> #include <linux/power_supply.h> #include <linux/platform_data/x86/apple.h> +#include <acpi/battery.h> #include "sbshc.h" -#include "battery.h" #define PREFIX "ACPI: "
include/acpi/battery.h new file +21 -0
@@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ACPI_BATTERY_H +#define __ACPI_BATTERY_H + +#define ACPI_BATTERY_CLASS "battery" + +#define ACPI_BATTERY_NOTIFY_STATUS 0x80 +#define ACPI_BATTERY_NOTIFY_INFO 0x81 +#define ACPI_BATTERY_NOTIFY_THRESHOLD 0x82 + +struct acpi_battery_hook { +const char *name; +int (*add_battery)(struct power_supply *battery); +int (*remove_battery)(struct power_supply *battery); +struct list_head list; +}; + +void battery_hook_register (struct acpi_battery_hook *hook); +void battery_hook_unregister (struct acpi_battery_hook *hook); + +#endif
Signature · 1 line
2.7.4
Andy Shevchenko
Quoted 19 lines · Ognjen Galic
This is a patch that implements a generic hooking API for the generic ACPI battery driver.
With this new generic API, drivers can expose platform specific behaviour via sysfs attributes in
/sys/class/power_supply/BATn/in a generic way.A perfect example of the need for this API are Lenovo ThinkPads.
Lenovo ThinkPads have a ACPI extension that allows the setting of start and stop charge thresholds in the EC and battery firmware via ACPI. The
thinkpad_acpimodule can use this API to expose sysfs attributes that it controls inside the ACPI battery driver sysfs tree, under/sys/class/power_supply/BATN/.The file
drivers/acpi/battery.hhas been moved toinclude/acpi/battery.hand the includes insideac.c,sbs.c, andbattery.chave been adjusted to reflect that.
Quoted 5 lines
When drivers hooks into the API, the API calls
add_battery()for each battery in the system that passes it aacpi_batterystruct. Then, the drivers can usedevice_create_file()to create new sysfs attributes with that struct and identify the batteries for per-battery attributes.
Thanks for an update. I have couple of minors. Otherwise look pretty much good!
Quoted 2 lines
drivers/acpi/battery.h | 11 ---- include/acpi/battery.h | 21 +++++++
There are -M and -C command line parameters to git format-patch. They can take an optional argument (percentage) of threshold.
Playing with those numbers you can achieve
rename ...
line and see actual diff.
No need to resend because of this. Just an explanation for the future Git work.
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 650
Quoted 4 lines
drivers/acpi/battery.c +4
-0+void __battery_hook_unregister (struct acpi_battery_hook *hook,int lock) +{ +struct list_head *position; +struct acpi_battery *battery;
Missed empty line?
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 658
Quoted 9 lines
drivers/acpi/battery.c +8
-0+/* +* In order to remove a hook, we first need to +* de-register all the batteries that are registered. +*/ +if (lock) +mutex_lock (&hook_mutex); +list_for_each (position, &acpi_battery_list) { + battery = list_entry(position, struct acpi_battery, list);
list_for_each_enrty() ?
Or I'm missing something why it can't be used?
Quoted 8 lines
drivers/acpi/battery.c +6
-0+ hook->remove_battery (battery->bat); + } +void battery_hook_register (struct acpi_battery_hook *hook) +{ +struct acpi_battery *battery; +list_for_each_entry (battery, &acpi_battery_list, list) {
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 695
Quoted 10 lines
drivers/acpi/battery.c +9
-0+if (hook->add_battery (battery->bat)) { +/* +* If a add-battery returns non-zero, +* the registration of the extension has failed, +* and we will not add it to the list of loaded +* hooks. +*/ +pr_err ("extension failed to load: %s" , + hook->name);
Can it fit 80 characters?
I mean if it would be one line...
Quoted 6 lines
drivers/acpi/battery.c +6
-0+__battery_hook_unregister (hook,0 ); +return ; + } + } +pr_info ("new extension: %s\n" , hook->name); +mutex_unlock (&hook_mutex);
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 711
Quoted 10 lines
drivers/acpi/battery.c +8
-0+} +static void battery_hook_add_battery (struct acpi_battery *battery) +{ +/* +* This function gets called right after the battery sysfs +* attributes have been added, so that the drivers that +* define custom sysfs attributes can add their own. +*/
Perhaps it should go before function definition.
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 758
Quoted 9 lines
drivers/acpi/battery.c +6
-0+struct acpi_battery_hook *hook_node; +} +static void __exit battery_hook_exit(void) +{ +struct acpi_battery_hook *hook; +struct acpi_battery_hook *ptr;
Missed empty line?
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 763
Quoted 5 lines
drivers/acpi/battery.c +5
-0+/* +* At this point, the acpi_bus_unregister_driver +* has called remove for all batteries. We just +* need to remove the hooks. +*/
A common pattern to use func() [note parens] when refer to function.
drivers/acpi/battery.c static int sysfs_add_battery(struct acpi_battery *battery) · line 794
Quoted 13 lines
drivers/acpi/battery.c +7
-0+list_for_each_entry_safe (hook, ptr, &battery_hook_list, list) { +__battery_hook_unregister (hook,1 ); + } +mutex_destroy (&hook_mutex); +} battery->bat =power_supply_register_no_ws (&battery->device->dev, &battery->bat_desc, &psy_cfg); +battery_hook_add_battery (battery); +if (IS_ERR (battery->bat)) {int result =PTR_ERR (battery->bat);
I'm not sure why you need to add hook when power_supply_register_no_ws() failed.
drivers/acpi/battery.c static void sysfs_remove_battery(struct acpi_battery *battery) · line 809
Quoted 3 lines
}drivers/acpi/battery.c +1
-1- +battery_hook_remove_battery (battery);
No need to remove an empty line.
Signature · 2 lines
With Best Regards, Andy Shevchenko
Quoted 34 lines · Andy Shevchenko
Quoted 19 lines · Ognjen Galic
This is a patch that implements a generic hooking API for the generic ACPI battery driver.
With this new generic API, drivers can expose platform specific behaviour via sysfs attributes in
/sys/class/power_supply/BATn/in a generic way.A perfect example of the need for this API are Lenovo ThinkPads.
Lenovo ThinkPads have a ACPI extension that allows the setting of start and stop charge thresholds in the EC and battery firmware via ACPI. The
thinkpad_acpimodule can use this API to expose sysfs attributes that it controls inside the ACPI battery driver sysfs tree, under/sys/class/power_supply/BATN/.The file
drivers/acpi/battery.hhas been moved toinclude/acpi/battery.hand the includes insideac.c,sbs.c, andbattery.chave been adjusted to reflect that.Quoted 5 lines
When drivers hooks into the API, the API calls
add_battery()for each battery in the system that passes it aacpi_batterystruct. Then, the drivers can usedevice_create_file()to create new sysfs attributes with that struct and identify the batteries for per-battery attributes.Thanks for an update. I have couple of minors. Otherwise look pretty much good!
Quoted 2 lines
drivers/acpi/battery.h | 11 ---- include/acpi/battery.h | 21 +++++++There are -M and -C command line parameters to git format-patch. They can take an optional argument (percentage) of threshold.
Quoted 7 lines
Playing with those numbers you can achieve
rename ...
line and see actual diff.
No need to resend because of this. Just an explanation for the future Git work.
I did use thos options. I used the following command:
git format-patch -M -C --notes -v12 -o ~/patches/. @^^^^
I really don't know what you are targeting. :)
Quoted 7 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 650
Quoted 5 lines
drivers/acpi/battery.c +4
-0+void __battery_hook_unregister (struct acpi_battery_hook *hook,int lock) +{ +struct list_head *position; +struct acpi_battery *battery;Missed empty line?
checkpatch.pl complains if there are NOT empty lines between declarations and statements.
Quoted 8 lines
Quoted 7 lines
drivers/acpi/battery.c +6
-0+/* +* In order to remove a hook, we first need to +* de-register all the batteries that are registered. +*/ +if (lock) +mutex_lock (&hook_mutex);
Quoted 6 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 658
Quoted 2 lines
drivers/acpi/battery.c +2
-0+list_for_each (position, &acpi_battery_list) { + battery = list_entry(position, struct acpi_battery, list);
list_for_each_enrty()?Or I'm missing something why it can't be used?
I missed that one. Bummer.
I mean, it's not game-breaking, its just minor style stuff. I won't be sending more revisions because of these small issues, as I think its uneccessary to flood both Rafael and the mailing lists with patch revisions that remove or add a few spaces. No offence, it just got old.
:)
Quoted 17 lines
Quoted 16 lines
drivers/acpi/battery.c +13
-0+ hook->remove_battery (battery->bat); + } +void battery_hook_register (struct acpi_battery_hook *hook) +{ +struct acpi_battery *battery; +list_for_each_entry (battery, &acpi_battery_list, list) { +if (hook->add_battery (battery->bat)) { +/* +* If a add-battery returns non-zero, +* the registration of the extension has failed, +* and we will not add it to the list of loaded +* hooks. +*/
Quoted 5 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 695
Quoted 2 lines
drivers/acpi/battery.c +2
-0+pr_err ("extension failed to load: %s" , + hook->name);Can it fit 80 characters?
I mean if it would be one line...
It could, but it does not. :)
Quoted 25 lines
Quoted 7 lines
drivers/acpi/battery.c +6
-0+__battery_hook_unregister (hook,0 ); +return ; + } + } +pr_info ("new extension: %s\n" , hook->name); +mutex_unlock (&hook_mutex);drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 711
Quoted 10 lines
drivers/acpi/battery.c +8
-0+} +static void battery_hook_add_battery (struct acpi_battery *battery) +{ +/* +* This function gets called right after the battery sysfs +* attributes have been added, so that the drivers that +* define custom sysfs attributes can add their own. +*/ Perhaps it should go before function definition.
Quoted 3 lines
drivers/acpi/battery.c +2
-0+struct acpi_battery_hook *hook_node; +}
Quoted 6 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 758
Quoted 4 lines
drivers/acpi/battery.c +4
-0+static void __exit battery_hook_exit(void) +{ +struct acpi_battery_hook *hook; +struct acpi_battery_hook *ptr;Missed empty line?
See above about the checkpatch.pl stuff.
Quoted 8 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 763
Quoted 6 lines
drivers/acpi/battery.c +5
-0+/* +* At this point, the acpi_bus_unregister_driver +* has called remove for all batteries. We just +* need to remove the hooks. +*/ A common pattern to use
func()[note parens] when refer to function.
Got it.
Quoted 10 lines
Quoted 10 lines
drivers/acpi/battery.c +5
-0+list_for_each_entry_safe (hook, ptr, &battery_hook_list, list) { +__battery_hook_unregister (hook,1 ); + } +mutex_destroy (&hook_mutex); +} battery->bat =power_supply_register_no_ws (&battery->device->dev, &battery->bat_desc, &psy_cfg);
Quoted 6 lines
drivers/acpi/battery.c static int sysfs_add_battery(struct acpi_battery *battery) · line 794
Quoted 4 lines
drivers/acpi/battery.c +2
-0+battery_hook_add_battery (battery); +if (IS_ERR (battery->bat)) {int result =PTR_ERR (battery->bat);I'm not sure why you need to add hook when
power_supply_register_no_ws()failed.
One could add a hook for other various reasons, not just to add or remove sysfs attributes. I'm talking stuff like desktop notifications or notifications to other modules to change power modes or other stuff.
Quoted 10 lines
drivers/acpi/battery.c static void sysfs_remove_battery(struct acpi_battery *battery) · line 809
Quoted 4 lines
}drivers/acpi/battery.c +1
-1- +battery_hook_remove_battery (battery);No need to remove an empty line.
Signature · 2 lines
With Best Regards, Andy Shevchenko
Andy Shevchenko
Quoted 5 lines · Ognjen Galić
Quoted 4 lines · Andy Shevchenko
On Wed, Jan 3, 2018 at 1:58 PM, Ognjen Galic <smclt30p(a)gmail.com> wrote:
Thanks for an update. I have couple of minors. Otherwise look pretty much good!
Quoted 8 lines
Quoted 8 lines
Quoted 2 lines
drivers/acpi/battery.h | 11 ---- include/acpi/battery.h | 21 +++++++There are -M and -C command line parameters to git format-patch.
They can take an optional argument (percentage) of threshold.
Playing with those numbers you can achieve
^^^^ Pay attention to the above
Quoted 5 lines
Quoted 5 lines
rename ...
line and see actual diff.
Quoted 7 lines
Quoted 1 line
No need to resend because of this. Just an explanation for the future Git work.
I did use thos options. I used the following command:
git format-patch -M -C --notes -v12 -o ~/patches/. @^^^^
I really don't know what you are targeting. :)
Please, read what I wrote above and the manual of git-format-patch.
Quoted 9 lines
Quoted 6 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 650
Quoted 4 lines
drivers/acpi/battery.c +4
-0+void __battery_hook_unregister (struct acpi_battery_hook *hook,int lock) +{ +struct list_head *position; +struct acpi_battery *battery;Missed empty line?
checkpatch.pl complains if there are NOT empty lines between declarations and statements.
checkpatch some times on one hand complains about something which it should not, on the other didn't take into consideration cases like this one.
Your statement started with comment, btw.
Quoted 11 lines
Quoted 6 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 656
Quoted 6 lines
drivers/acpi/battery.c +6
-0+/* +* In order to remove a hook, we first need to +* de-register all the batteries that are registered. +*/ +if (lock) +mutex_lock (&hook_mutex);I mean, it's not game-breaking, its just minor style stuff. I won't be sending more revisions because of these small issues, as I think its uneccessary to flood both Rafael and the mailing lists with patch revisions that remove or add a few spaces. No offence, it just got old.
Yes, his call anyway to apply or ask you for amendments. I'm just helping with review.
Quoted 8 lines
Quoted 6 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 758
Quoted 4 lines
drivers/acpi/battery.c +4
-0+static void __exit battery_hook_exit(void) +{ +struct acpi_battery_hook *hook; +struct acpi_battery_hook *ptr;Missed empty line?
See above about the checkpatch.pl stuff.
See above the answer.
Signature · 2 lines
With Best Regards, Andy Shevchenko
Quoted 55 lines · Andy Shevchenko
Quoted 5 lines · Ognjen Galić
Quoted 4 lines · Andy Shevchenko
On Wed, Jan 3, 2018 at 1:58 PM, Ognjen Galic <[email protected]> wrote:
Thanks for an update. I have couple of minors. Otherwise look pretty much good!
Quoted 8 lines
Quoted 8 lines
Quoted 2 lines
drivers/acpi/battery.h | 11 ---- include/acpi/battery.h | 21 +++++++There are -M and -C command line parameters to git format-patch.
They can take an optional argument (percentage) of threshold.
Playing with those numbers you can achieve
^^^^ Pay attention to the above
Quoted 5 lines
Quoted 5 lines
rename ...
line and see actual diff.
Quoted 7 lines
Quoted 1 line
No need to resend because of this. Just an explanation for the future Git work.
I did use thos options. I used the following command:
git format-patch -M -C --notes -v12 -o ~/patches/. @^^^^
I really don't know what you are targeting. :)
Please, read what I wrote above and the manual of git-format-patch.
Quoted 9 lines
Quoted 6 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 650
Quoted 4 lines
drivers/acpi/battery.c +4
-0+void __battery_hook_unregister (struct acpi_battery_hook *hook,int lock) +{ +struct list_head *position; +struct acpi_battery *battery;Missed empty line?
checkpatch.pl complains if there are NOT empty lines between declarations and statements.
checkpatch some times on one hand complains about something which it should not, on the other didn't take into consideration cases like this one.
Your statement started with comment, btw.
Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
drivers/acpi/battery.c +6
-0+/* +* In order to remove a hook, we first need to +* de-register all the batteries that are registered. +*/ +if (lock) +mutex_lock (&hook_mutex);
Quoted 7 lines
Quoted 4 lines
I mean, it's not game-breaking, its just minor style stuff. I won't be sending more revisions because of these small issues, as I think its uneccessary to flood both Rafael and the mailing lists with patch revisions that remove or add a few spaces. No offence, it just got old.
Yes, his call anyway to apply or ask you for amendments. I'm just helping with review.
Rafael, what do you think? Do you want these style/syntax issues fixed or is it good to go?
Thanks for the time to review Andy! You are a champ! :)
Quoted 16 lines
Quoted 9 lines
Quoted 7 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 758
Quoted 5 lines
drivers/acpi/battery.c +4
-0+static void __exit battery_hook_exit(void) +{ +struct acpi_battery_hook *hook; +struct acpi_battery_hook *ptr;Missed empty line?
See above about the checkpatch.pl stuff.
See above the answer.
Signature · 2 lines
With Best Regards, Andy Shevchenko
Rafael J. Wysocki
Quoted 61 lines · Ognjen Galić
Quoted 60 lines · Andy Shevchenko
Quoted 5 lines · Ognjen Galić
Quoted 4 lines · Andy Shevchenko
On Wed, Jan 3, 2018 at 1:58 PM, Ognjen Galic <smclt30p(a)gmail.com> wrote:
Thanks for an update. I have couple of minors. Otherwise look pretty much good!
Quoted 8 lines
Quoted 8 lines
Quoted 2 lines
drivers/acpi/battery.h | 11 ---- include/acpi/battery.h | 21 +++++++There are -M and -C command line parameters to git format-patch.
They can take an optional argument (percentage) of threshold.
Playing with those numbers you can achieve
^^^^ Pay attention to the above
Quoted 5 lines
Quoted 5 lines
rename ...
line and see actual diff.
Quoted 7 lines
Quoted 1 line
No need to resend because of this. Just an explanation for the future Git work.
I did use thos options. I used the following command:
git format-patch -M -C --notes -v12 -o ~/patches/. @^^^^
I really don't know what you are targeting. :)
Please, read what I wrote above and the manual of git-format-patch.
Quoted 9 lines
Quoted 6 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 650
Quoted 4 lines
drivers/acpi/battery.c +4
-0+void __battery_hook_unregister (struct acpi_battery_hook *hook,int lock) +{ +struct list_head *position; +struct acpi_battery *battery;Missed empty line?
checkpatch.pl complains if there are NOT empty lines between declarations and statements.
checkpatch some times on one hand complains about something which it should not, on the other didn't take into consideration cases like this one.
Your statement started with comment, btw.
Quoted 11 lines
Quoted 6 lines
drivers/acpi/battery.c static const struct device_attribute alarm_attr = { · line 656
Quoted 6 lines
drivers/acpi/battery.c +6
-0+/* +* In order to remove a hook, we first need to +* de-register all the batteries that are registered. +*/ +if (lock) +mutex_lock (&hook_mutex);I mean, it's not game-breaking, its just minor style stuff. I won't be sending more revisions because of these small issues, as I think its uneccessary to flood both Rafael and the mailing lists with patch revisions that remove or add a few spaces. No offence, it just got old.
Quoted 5 lines
Quoted 2 lines
Yes, his call anyway to apply or ask you for amendments. I'm just helping with review.
Rafael, what do you think? Do you want these style/syntax issues fixed or is it good to go?
As long as the code is all correct technically, they are secondary.
That said I still need to look into your patches in detail and I need more time for that.
Thanks,
Rafael
Rafael J. Wysocki
Quoted 253 lines · CET Ognjen Galic
This is a patch that implements a generic hooking API for the generic ACPI battery driver.
With this new generic API, drivers can expose platform specific behaviour via sysfs attributes in
/sys/class/power_supply/BATn/in a generic way.A perfect example of the need for this API are Lenovo ThinkPads.
Lenovo ThinkPads have a ACPI extension that allows the setting of start and stop charge thresholds in the EC and battery firmware via ACPI. The
thinkpad_acpimodule can use this API to expose sysfs attributes that it controls inside the ACPI battery driver sysfs tree, under/sys/class/power_supply/BATN/.The file
drivers/acpi/battery.hhas been moved toinclude/acpi/battery.hand the includes insideac.c,sbs.c, andbattery.chave been adjusted to reflect that.When drivers hooks into the API, the API calls
add_battery()for each battery in the system that passes it aacpi_batterystruct. Then, the drivers can usedevice_create_file()to create new sysfs attributes with that struct and identify the batteries for per-battery attributes.Signed-off-by Ognjen Galic <smclt30p(a)gmail.com>---
Notes:
v7:
* Implemented mutual exclusion for hooking methods and battery callbacks
* Fixed a BUG where errors in other modules would occur when the modules that depend on battery get unloadedv8:
* Uselist_for_each_safeinstead oflist_for_eachfor the module exit function where deletion of nodes occursv9:
* No changes in this patch in v9v10:
* Fix compiler warnings in Intel's 0-day CIv11:
* Fix changelog formatting
* Make lists and mutex staticv12:
* Change all applicablelist_for_eachtolist_for_each_entry
* Definepr_fmtto include module name for pr_*drivers/acpi/ac.c | 2 +- drivers/acpi/battery.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++- drivers/acpi/battery.h | 11 ---- drivers/acpi/sbs.c | 2 +- include/acpi/battery.h | 21 +++++++ 5 files changed, 171 insertions(+), 16 deletions(-) delete mode 100644 drivers/acpi/battery.h create mode 100644 include/acpi/battery.hdrivers/acpi/ac.c +1
-1@@ -33,7 +33,7 @@#include <linux/platform_device.h> #include <linux/power_supply.h> #include <linux/acpi.h> -#include "battery.h" +#include <acpi/battery.h> #define PREFIX "ACPI: "drivers/acpi/battery.c +142
-1@@ -21,8 +21,12 @@* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ +#define pr_fmt (fmt) KBUILD_MODNAME ": " fmt +#include <linux/kernel.h> +#include <linux/list.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/init.h> #include <linux/types.h> #include <linux/jiffies.h> @@ -42,7 +46,7 @@#include <linux/acpi.h> #include <linux/power_supply.h> -#include "battery.h" +#include <acpi/battery.h> #define PREFIX "ACPI: "@@ -124,6 +128,7 @@ struct acpi_battery {struct power_supply_desc bat_desc;struct acpi_device *device;struct notifier_block pm_nb; +struct list_head list;unsigned long update_time;int revision;int rate_now;@@ -626,6 +631,142 @@ static const struct device_attribute alarm_attr = { .store = acpi_battery_alarm_store, }; +/* +* The Battery Hooking API +* +* This API is used inside other drivers that need to expose +* platform-specific behaviour within the generic driver in a +* generic way. +* +*/ + +static LIST_HEAD (acpi_battery_list); +static LIST_HEAD (battery_hook_list); +static DEFINE_MUTEX (hook_mutex); + +void __battery_hook_unregister (struct acpi_battery_hook *hook,int lock) +{ +struct list_head *position; +struct acpi_battery *battery; +/* +* In order to remove a hook, we first need to +* de-register all the batteries that are registered. +*/ +if (lock) +mutex_lock (&hook_mutex); +list_for_each (position, &acpi_battery_list) { + battery = list_entry(position, struct acpi_battery, list); + hook->remove_battery (battery->bat); + } +list_del (&hook->list); +if (lock) +mutex_unlock (&hook_mutex); +pr_info ("extension unregistered: %s\n" , hook->name); +} + +void battery_hook_unregister (struct acpi_battery_hook *hook) +{ +__battery_hook_unregister (hook,1 ); +} +EXPORT_SYMBOL_GPL (battery_hook_unregister); + +void battery_hook_register (struct acpi_battery_hook *hook) +{ +struct acpi_battery *battery; + +mutex_lock (&hook_mutex); +INIT_LIST_HEAD (&hook->list); +list_add (&hook->list, &battery_hook_list); +/* +* Now that the driver is registered, we need +* to notify the hook that a battery is available +* for each battery, so that the driver may add +* its attributes. +*/ +list_for_each_entry (battery, &acpi_battery_list, list) { +if (hook->add_battery (battery->bat)) { +/* +* If a add-battery returns non-zero, +* the registration of the extension has failed, +* and we will not add it to the list of loaded +* hooks. +*/ +pr_err ("extension failed to load: %s" , + hook->name); +__battery_hook_unregister (hook,0 ); +return ; + } + } +pr_info ("new extension: %s\n" , hook->name); +mutex_unlock (&hook_mutex); +} +EXPORT_SYMBOL_GPL (battery_hook_register); + +static void battery_hook_add_battery (struct acpi_battery *battery) +{ +/* +* This function gets called right after the battery sysfs +* attributes have been added, so that the drivers that +* define custom sysfs attributes can add their own. +*/ +struct acpi_battery_hook *hook_node; + +mutex_lock (&hook_mutex); +INIT_LIST_HEAD (&battery->list); +list_add (&battery->list, &acpi_battery_list); +/* +* Since we added a new battery to the list, we need to +* iterate over the hooks and call add_battery for each +* hook that was registered. This usually happens +* when a battery gets hotplugged or initialized +* during the battery module initialization. +*/ +list_for_each_entry (hook_node, &battery_hook_list, list) { +if (hook_node->add_battery (battery->bat)) { +/* +* The notification of the extensions has failed, to +* prevent further errors we will unload the extension. +*/ +__battery_hook_unregister (hook_node,0 ); +pr_err ("error in extension, unloading: %s" , + hook_node->name); + } + } +mutex_unlock (&hook_mutex); +} + +static void battery_hook_remove_battery (struct acpi_battery *battery) +{ +struct acpi_battery_hook *hook; + +mutex_lock (&hook_mutex); +/* +* Before removing the hook, we need to remove all +* custom attributes from the battery. +*/ +list_for_each_entry (hook, &battery_hook_list, list) { + hook->remove_battery (battery->bat); + } +/* Then, just remove the battery from the list */ +list_del (&battery->list); +mutex_unlock (&hook_mutex); +} + +static void __exit battery_hook_exit(void) +{ +struct acpi_battery_hook *hook; +struct acpi_battery_hook *ptr; +/* +* At this point, the acpi_bus_unregister_driver +* has called remove for all batteries. We just +* need to remove the hooks. +*/ +list_for_each_entry_safe (hook, ptr, &battery_hook_list, list) { +__battery_hook_unregister (hook,1 ); + } +mutex_destroy (&hook_mutex); +} +static int sysfs_add_battery (struct acpi_battery *battery) {struct power_supply_config psy_cfg = { .drv_data = battery, };
drivers/acpi/battery.c static int sysfs_add_battery(struct acpi_battery *battery) · line 791
Quoted 4 lines
drivers/acpi/battery.c +1
-0@@ -647,6 +788,8 @@ static int sysfs_add_battery(struct acpi_battery *battery) battery->bat =power_supply_register_no_ws (&battery->device->dev, &battery->bat_desc, &psy_cfg); +battery_hook_add_battery (battery);
I seem to see a problem here, as this may be called before battery_hook_register() in some cases if I'm not mistaken and there seems to be nothing to ensure that the "hook" code will actually see the battery then.
Thanks,
Rafael
Quoted 257 lines · Rafael J. Wysocki
Quoted 256 lines · CET Ognjen Galic
This is a patch that implements a generic hooking API for the generic ACPI battery driver.
With this new generic API, drivers can expose platform specific behaviour via sysfs attributes in
/sys/class/power_supply/BATn/in a generic way.A perfect example of the need for this API are Lenovo ThinkPads.
Lenovo ThinkPads have a ACPI extension that allows the setting of start and stop charge thresholds in the EC and battery firmware via ACPI. The
thinkpad_acpimodule can use this API to expose sysfs attributes that it controls inside the ACPI battery driver sysfs tree, under/sys/class/power_supply/BATN/.The file
drivers/acpi/battery.hhas been moved toinclude/acpi/battery.hand the includes insideac.c,sbs.c, andbattery.chave been adjusted to reflect that.When drivers hooks into the API, the API calls
add_battery()for each battery in the system that passes it aacpi_batterystruct. Then, the drivers can usedevice_create_file()to create new sysfs attributes with that struct and identify the batteries for per-battery attributes.Signed-off-by Ognjen Galic <[email protected]>---
Notes:
v7:
* Implemented mutual exclusion for hooking methods and battery callbacks
* Fixed a BUG where errors in other modules would occur when the modules that depend on battery get unloadedv8:
* Uselist_for_each_safeinstead oflist_for_eachfor the module exit function where deletion of nodes occursv9:
* No changes in this patch in v9v10:
* Fix compiler warnings in Intel's 0-day CIv11:
* Fix changelog formatting
* Make lists and mutex staticv12:
* Change all applicablelist_for_eachtolist_for_each_entry
* Definepr_fmtto include module name for pr_*drivers/acpi/ac.c | 2 +- drivers/acpi/battery.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++- drivers/acpi/battery.h | 11 ---- drivers/acpi/sbs.c | 2 +- include/acpi/battery.h | 21 +++++++ 5 files changed, 171 insertions(+), 16 deletions(-) delete mode 100644 drivers/acpi/battery.h create mode 100644 include/acpi/battery.hdrivers/acpi/ac.c +1
-1@@ -33,7 +33,7 @@#include <linux/platform_device.h> #include <linux/power_supply.h> #include <linux/acpi.h> -#include "battery.h" +#include <acpi/battery.h> #define PREFIX "ACPI: "drivers/acpi/battery.c +142
-1@@ -21,8 +21,12 @@* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ +#define pr_fmt (fmt) KBUILD_MODNAME ": " fmt +#include <linux/kernel.h> +#include <linux/list.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/init.h> #include <linux/types.h> #include <linux/jiffies.h> @@ -42,7 +46,7 @@#include <linux/acpi.h> #include <linux/power_supply.h> -#include "battery.h" +#include <acpi/battery.h> #define PREFIX "ACPI: "@@ -124,6 +128,7 @@ struct acpi_battery {struct power_supply_desc bat_desc;struct acpi_device *device;struct notifier_block pm_nb; +struct list_head list;unsigned long update_time;int revision;int rate_now;@@ -626,6 +631,142 @@ static const struct device_attribute alarm_attr = { .store = acpi_battery_alarm_store, }; +/* +* The Battery Hooking API +* +* This API is used inside other drivers that need to expose +* platform-specific behaviour within the generic driver in a +* generic way. +* +*/ + +static LIST_HEAD (acpi_battery_list); +static LIST_HEAD (battery_hook_list); +static DEFINE_MUTEX (hook_mutex); + +void __battery_hook_unregister (struct acpi_battery_hook *hook,int lock) +{ +struct list_head *position; +struct acpi_battery *battery; +/* +* In order to remove a hook, we first need to +* de-register all the batteries that are registered. +*/ +if (lock) +mutex_lock (&hook_mutex); +list_for_each (position, &acpi_battery_list) { + battery = list_entry(position, struct acpi_battery, list); + hook->remove_battery (battery->bat); + } +list_del (&hook->list); +if (lock) +mutex_unlock (&hook_mutex); +pr_info ("extension unregistered: %s\n" , hook->name); +} + +void battery_hook_unregister (struct acpi_battery_hook *hook) +{ +__battery_hook_unregister (hook,1 ); +} +EXPORT_SYMBOL_GPL (battery_hook_unregister); + +void battery_hook_register (struct acpi_battery_hook *hook) +{ +struct acpi_battery *battery; + +mutex_lock (&hook_mutex); +INIT_LIST_HEAD (&hook->list); +list_add (&hook->list, &battery_hook_list); +/* +* Now that the driver is registered, we need +* to notify the hook that a battery is available +* for each battery, so that the driver may add +* its attributes. +*/ +list_for_each_entry (battery, &acpi_battery_list, list) { +if (hook->add_battery (battery->bat)) { +/* +* If a add-battery returns non-zero, +* the registration of the extension has failed, +* and we will not add it to the list of loaded +* hooks. +*/ +pr_err ("extension failed to load: %s" , + hook->name); +__battery_hook_unregister (hook,0 ); +return ; + } + } +pr_info ("new extension: %s\n" , hook->name); +mutex_unlock (&hook_mutex); +} +EXPORT_SYMBOL_GPL (battery_hook_register); + +static void battery_hook_add_battery (struct acpi_battery *battery) +{ +/* +* This function gets called right after the battery sysfs +* attributes have been added, so that the drivers that +* define custom sysfs attributes can add their own. +*/ +struct acpi_battery_hook *hook_node; + +mutex_lock (&hook_mutex); +INIT_LIST_HEAD (&battery->list); +list_add (&battery->list, &acpi_battery_list); +/* +* Since we added a new battery to the list, we need to +* iterate over the hooks and call add_battery for each +* hook that was registered. This usually happens +* when a battery gets hotplugged or initialized +* during the battery module initialization. +*/ +list_for_each_entry (hook_node, &battery_hook_list, list) { +if (hook_node->add_battery (battery->bat)) { +/* +* The notification of the extensions has failed, to +* prevent further errors we will unload the extension. +*/ +__battery_hook_unregister (hook_node,0 ); +pr_err ("error in extension, unloading: %s" , + hook_node->name); + } + } +mutex_unlock (&hook_mutex); +} + +static void battery_hook_remove_battery (struct acpi_battery *battery) +{ +struct acpi_battery_hook *hook; + +mutex_lock (&hook_mutex); +/* +* Before removing the hook, we need to remove all +* custom attributes from the battery. +*/ +list_for_each_entry (hook, &battery_hook_list, list) { + hook->remove_battery (battery->bat); + } +/* Then, just remove the battery from the list */ +list_del (&battery->list); +mutex_unlock (&hook_mutex); +} + +static void __exit battery_hook_exit(void) +{ +struct acpi_battery_hook *hook; +struct acpi_battery_hook *ptr; +/* +* At this point, the acpi_bus_unregister_driver +* has called remove for all batteries. We just +* need to remove the hooks. +*/ +list_for_each_entry_safe (hook, ptr, &battery_hook_list, list) { +__battery_hook_unregister (hook,1 ); + } +mutex_destroy (&hook_mutex); +} +static int sysfs_add_battery (struct acpi_battery *battery) {struct power_supply_config psy_cfg = { .drv_data = battery, };@@ -647,6 +788,8 @@ static int sysfs_add_battery(struct acpi_battery *battery) battery->bat =power_supply_register_no_ws (&battery->device->dev, &battery->bat_desc, &psy_cfg);
Quoted 5 lines
drivers/acpi/battery.c static int sysfs_add_battery(struct acpi_battery *battery) · line 791
Quoted 1 line
drivers/acpi/battery.c +1
-0+battery_hook_add_battery (battery);I seem to see a problem here, as this may be called before
battery_hook_register()in some cases if I'm not mistaken and there seems to be nothing to ensure that the "hook" code will actually see the battery then.
There is a mechanism for late-loading of modules. battery_hook_add_battery adds each battery to a list of batteries:
Quoted 1 line
static
LIST_HEAD(acpi_battery_list);
When the ACPI battery drivers adds a battery to sysfs, the call to battery_hook_add_battery adds the battery to the list that is being added.
Quoted 7 lines
...
struct acpi_battery_hook *hook_node; mutex_lock(&hook_mutex); INIT_LIST_HEAD(&battery->list); list_add(&battery->list, &acpi_battery_list);...
Then, after adding the battery to the list it notifies the already existing hooks of the new battery:
Quoted 7 lines
list_for_each_entry(hook_node, &battery_hook_list, list) {
if (hook_node->add_battery(battery->bat)) {
__battery_hook_unregister(hook_node, 0);
pr_err("error in extension, unloading: %s",
hook_node->name);
}
}If and and after some module calls battery_hook_register AFTER the battery has been added, the module is THEN notified of ALL the batteries added to sysfs, regardless of loading time or hooking of that module.
Quoted 6 lines
list_for_each_entry(battery, &acpi_battery_list, list) {
if (hook->add_battery(battery->bat)) {
/*
* If a add-battery returns non-zero,
* the registration of the extension has failed,
* and we will not add it to the list of loadedQuoted 8 lines
* hooks.
*/
pr_err("extension failed to load: %s",
hook->name);
__battery_hook_unregister(hook, 0);
return;
}
}The order is like this for late hook loading:
* battery module loads
* battery constructs a list of batteries
* battery is ready
And some other module that NEEDS the battery hook API *MUST* load *AFTER* battery, and it will *NOT* load if battery is not loaded. It fails with a pre-load "symbol missing" error, *NOT* a runtime error.
* thinkpad_acpi loads
* thinkpad_acpi hooks into battery
* battery goes through the list of batteries and registers then in thinkpad_acpi
* thinkpad_acpi is ready
I tested this back and forth, removing batteries, adding them, loading then adding batteries, back and forth and it registers the battery each time.
Thanks for the time.
Ognjen
Quoted 4 lines
Thanks,
Rafael
Rafael J. Wysocki
Quoted 258 lines · Ognjen Galić
Quoted 257 lines · Rafael J. Wysocki
Quoted 256 lines · CET Ognjen Galic
This is a patch that implements a generic hooking API for the generic ACPI battery driver.
With this new generic API, drivers can expose platform specific behaviour via sysfs attributes in
/sys/class/power_supply/BATn/in a generic way.A perfect example of the need for this API are Lenovo ThinkPads.
Lenovo ThinkPads have a ACPI extension that allows the setting of start and stop charge thresholds in the EC and battery firmware via ACPI. The
thinkpad_acpimodule can use this API to expose sysfs attributes that it controls inside the ACPI battery driver sysfs tree, under/sys/class/power_supply/BATN/.The file
drivers/acpi/battery.hhas been moved toinclude/acpi/battery.hand the includes insideac.c,sbs.c, andbattery.chave been adjusted to reflect that.When drivers hooks into the API, the API calls
add_battery()for each battery in the system that passes it aacpi_batterystruct. Then, the drivers can usedevice_create_file()to create new sysfs attributes with that struct and identify the batteries for per-battery attributes.Signed-off-by Ognjen Galic <smclt30p(a)gmail.com>---
Notes:
v7:
* Implemented mutual exclusion for hooking methods and battery callbacks
* Fixed a BUG where errors in other modules would occur when the modules that depend on battery get unloadedv8:
* Uselist_for_each_safeinstead oflist_for_eachfor the module exit function where deletion of nodes occursv9:
* No changes in this patch in v9v10:
* Fix compiler warnings in Intel's 0-day CIv11:
* Fix changelog formatting
* Make lists and mutex staticv12:
* Change all applicablelist_for_eachtolist_for_each_entry
* Definepr_fmtto include module name for pr_*drivers/acpi/ac.c | 2 +- drivers/acpi/battery.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++- drivers/acpi/battery.h | 11 ---- drivers/acpi/sbs.c | 2 +- include/acpi/battery.h | 21 +++++++ 5 files changed, 171 insertions(+), 16 deletions(-) delete mode 100644 drivers/acpi/battery.h create mode 100644 include/acpi/battery.hdrivers/acpi/ac.c +1
-1@@ -33,7 +33,7 @@#include <linux/platform_device.h> #include <linux/power_supply.h> #include <linux/acpi.h> -#include "battery.h" +#include <acpi/battery.h> #define PREFIX "ACPI: "drivers/acpi/battery.c +142
-1@@ -21,8 +21,12 @@* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ +#define pr_fmt (fmt) KBUILD_MODNAME ": " fmt +#include <linux/kernel.h> +#include <linux/list.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/init.h> #include <linux/types.h> #include <linux/jiffies.h> @@ -42,7 +46,7 @@#include <linux/acpi.h> #include <linux/power_supply.h> -#include "battery.h" +#include <acpi/battery.h> #define PREFIX "ACPI: "@@ -124,6 +128,7 @@ struct acpi_battery {struct power_supply_desc bat_desc;struct acpi_device *device;struct notifier_block pm_nb; +struct list_head list;unsigned long update_time;int revision;int rate_now;@@ -626,6 +631,142 @@ static const struct device_attribute alarm_attr = { .store = acpi_battery_alarm_store, }; +/* +* The Battery Hooking API +* +* This API is used inside other drivers that need to expose +* platform-specific behaviour within the generic driver in a +* generic way. +* +*/ + +static LIST_HEAD (acpi_battery_list); +static LIST_HEAD (battery_hook_list); +static DEFINE_MUTEX (hook_mutex); + +void __battery_hook_unregister (struct acpi_battery_hook *hook,int lock) +{ +struct list_head *position; +struct acpi_battery *battery; +/* +* In order to remove a hook, we first need to +* de-register all the batteries that are registered. +*/ +if (lock) +mutex_lock (&hook_mutex); +list_for_each (position, &acpi_battery_list) { + battery = list_entry(position, struct acpi_battery, list); + hook->remove_battery (battery->bat); + } +list_del (&hook->list); +if (lock) +mutex_unlock (&hook_mutex); +pr_info ("extension unregistered: %s\n" , hook->name); +} + +void battery_hook_unregister (struct acpi_battery_hook *hook) +{ +__battery_hook_unregister (hook,1 ); +} +EXPORT_SYMBOL_GPL (battery_hook_unregister); + +void battery_hook_register (struct acpi_battery_hook *hook) +{ +struct acpi_battery *battery; + +mutex_lock (&hook_mutex); +INIT_LIST_HEAD (&hook->list); +list_add (&hook->list, &battery_hook_list); +/* +* Now that the driver is registered, we need +* to notify the hook that a battery is available +* for each battery, so that the driver may add +* its attributes. +*/ +list_for_each_entry (battery, &acpi_battery_list, list) { +if (hook->add_battery (battery->bat)) { +/* +* If a add-battery returns non-zero, +* the registration of the extension has failed, +* and we will not add it to the list of loaded +* hooks. +*/ +pr_err ("extension failed to load: %s" , + hook->name); +__battery_hook_unregister (hook,0 ); +return ; + } + } +pr_info ("new extension: %s\n" , hook->name); +mutex_unlock (&hook_mutex); +} +EXPORT_SYMBOL_GPL (battery_hook_register); + +static void battery_hook_add_battery (struct acpi_battery *battery) +{ +/* +* This function gets called right after the battery sysfs +* attributes have been added, so that the drivers that +* define custom sysfs attributes can add their own. +*/ +struct acpi_battery_hook *hook_node; + +mutex_lock (&hook_mutex); +INIT_LIST_HEAD (&battery->list); +list_add (&battery->list, &acpi_battery_list); +/* +* Since we added a new battery to the list, we need to +* iterate over the hooks and call add_battery for each +* hook that was registered. This usually happens +* when a battery gets hotplugged or initialized +* during the battery module initialization. +*/ +list_for_each_entry (hook_node, &battery_hook_list, list) { +if (hook_node->add_battery (battery->bat)) { +/* +* The notification of the extensions has failed, to +* prevent further errors we will unload the extension. +*/ +__battery_hook_unregister (hook_node,0 ); +pr_err ("error in extension, unloading: %s" , + hook_node->name); + } + } +mutex_unlock (&hook_mutex); +} + +static void battery_hook_remove_battery (struct acpi_battery *battery) +{ +struct acpi_battery_hook *hook; + +mutex_lock (&hook_mutex); +/* +* Before removing the hook, we need to remove all +* custom attributes from the battery. +*/ +list_for_each_entry (hook, &battery_hook_list, list) { + hook->remove_battery (battery->bat); + } +/* Then, just remove the battery from the list */ +list_del (&battery->list); +mutex_unlock (&hook_mutex); +} + +static void __exit battery_hook_exit(void) +{ +struct acpi_battery_hook *hook; +struct acpi_battery_hook *ptr; +/* +* At this point, the acpi_bus_unregister_driver +* has called remove for all batteries. We just +* need to remove the hooks. +*/ +list_for_each_entry_safe (hook, ptr, &battery_hook_list, list) { +__battery_hook_unregister (hook,1 ); + } +mutex_destroy (&hook_mutex); +} +static int sysfs_add_battery (struct acpi_battery *battery) {struct power_supply_config psy_cfg = { .drv_data = battery, };@@ -647,6 +788,8 @@ static int sysfs_add_battery(struct acpi_battery *battery) battery->bat =power_supply_register_no_ws (&battery->device->dev, &battery->bat_desc, &psy_cfg);
Quoted 10 lines
Quoted 5 lines
drivers/acpi/battery.c static int sysfs_add_battery(struct acpi_battery *battery) · line 791
Quoted 1 line
drivers/acpi/battery.c +1
-0+battery_hook_add_battery (battery);I seem to see a problem here, as this may be called before
battery_hook_register()in some cases if I'm not mistaken and there seems to be nothing to ensure that the "hook" code will actually see the battery then.There is a mechanism for late-loading of modules.
battery_hook_add_batteryadds each battery to a list of batteries:Quoted 1 line
static
LIST_HEAD(acpi_battery_list);
OK, that should be fine then.
Please respin the series with the comments from Andy addressed and I will queue it up.
Thanks,
Rafael