On Mon, Feb 21, 2022 at 5:52 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
>
> On Fri, Feb 18, 2022 at 12:17 AM Carl Edquist <edquist@xxxxxxxxxxx> wrote:
> >
> > Hello there Rafael,
> >
> > (I found your contact in the MAINTAINERS file for the ACPI section.
> > Hopefully you are the right person to ask this question, but let me know
> > if there's a better place to ask!)
> >
> > Slackware 15 was released this month, and after upgrading (to linux
> > 5.15.19, according to uname -r), I noticed my wmpower dockapp for the
> > WindowMaker window manager stopped working. Apparently it relies on
> > /proc/acpi/battery, and does not know about the /sys alternatives. Maybe
> > it was written before this acpi interface was deprecated.
> >
> > Since wmpower has "just worked" for so long, it appears the only
> > maintenance it's received in a long time has been by the Slackware
> > packagers (slackbuilds.org) to fix compiler issues with more recent
> > versions of gcc. But people like me definitely still use it! :)
> >
> >
> > I tried searching a bit to see what's going on, and I found an earlier
> > discussion where /proc/acpi/battery had previously been removed, circa
> > linux 3.14, and then re-added, after it was brought up that (possibly
> > among other things) a number of WindowManager dock apps still relied on
> > /proc/acpi/battery:
> >
> > https://lkml.org/lkml/2014/3/17/393
> >
> >
> > I didn't find a more recent discussion about it getting removed again, but
> > some git-log searching brought me to this commit:
> >
> >
> > commit 8830280a69ddfdbba7fb24d79dce309817783c6a
> > Author: Thomas Renninger <trenn@xxxxxxx>
> > Date: Wed May 27 17:33:03 2020 +0200
> >
> > ACPI: procfs: Remove last dirs after being marked deprecated for a decade
> >
> > This code is outdated and has been deprecated for a long time, so user
> > space is not expected to rely on it any more on any systems that are
> > up to date by any reasonable measure. Remove it.
> >
> > Signed-off-by: Thomas Renninger <trenn@xxxxxxx>
> > [ rjw: Subject / changelog ]
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >
> >
> > Out of curiousity, I tried reverting this commit against the latest
> > master. It does not revert cleanly, though it doesn't look like a lot to
> > clean up (conflicts in drivers/acpi/ac.c & battery.c). Would reverting
> > this commit (assuming conflicts can be fixed) be enough for me to restore
> > the old /proc/acpi/battery interface?
>
> It should be sufficient.
>
> > Or are there likely to be any gotchas there?
> >
> >
> > And, I'm afraid to ask, but is it out of the question to wonder if this,
> > now twice removed, acpi interface may ever see its way back into mainline?
>
> Because we promise that user space won't be broken by kernel changes,
> it needs to be restored to make wmpower work again.
>
> I'd rather not restore all of it, though, just the part relied on by wmpower.
Please check if the attached patch (on top of 5.17-rc5) is sufficient
to restore the wmpower functionality.
From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Subject: [PATCH] ACPI: battery / AC: Restore the old proc interface
Restore the old proc interface for the ACPI battery and AC drivers,
removed by commit 8830280a69dd ("ACPI: procfs: Remove last dirs after
being marked deprecated for a decade") on the premise that it should
not be used any more, but in fact it is used by the wmpower utility
still shipped in Slackware 15 released this month.
Fixes: 8830280a69dd ("ACPI: procfs: Remove last dirs after being marked deprecated for a decade")
Reported-by: Carl Edquist <edquist@xxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/Kconfig | 17 +++
drivers/acpi/ac.c | 108 ++++++++++++++++++++-
drivers/acpi/battery.c | 252 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 375 insertions(+), 2 deletions(-)
Index: linux-pm/drivers/acpi/Kconfig
===================================================================
--- linux-pm.orig/drivers/acpi/Kconfig
+++ linux-pm/drivers/acpi/Kconfig
@@ -110,6 +110,23 @@ config ACPI_SLEEP
depends on ACPI_SYSTEM_POWER_STATES_SUPPORT
default y
+config ACPI_PROCFS_POWER
+ bool "Deprecated power /proc/acpi directories"
+ depends on X86 && PROC_FS
+ help
+ For backwards compatibility, this option allows
+ deprecated power /proc/acpi/ directories to exist, even when
+ they have been replaced by functions in /sys.
+ The deprecated directories (and their replacements) include:
+ /proc/acpi/battery/* (/sys/class/power_supply/*) and
+ /proc/acpi/ac_adapter/* (sys/class/power_supply/*).
+ This option has no effect on /proc/acpi/ directories
+ and functions which do not yet exist in /sys.
+ This option, together with the proc directories, will be
+ deleted in the future.
+
+ Say N to delete power /proc/acpi/ directories that have moved to /sys.
+
config ACPI_REV_OVERRIDE_POSSIBLE
bool "Allow supported ACPI revision to be overridden"
depends on X86
Index: linux-pm/drivers/acpi/ac.c
===================================================================
--- linux-pm.orig/drivers/acpi/ac.c
+++ linux-pm/drivers/acpi/ac.c
@@ -15,6 +15,10 @@
#include <linux/types.h>
#include <linux/dmi.h>
#include <linux/delay.h>
+#ifdef CONFIG_ACPI_PROCFS_POWER
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#endif
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/acpi.h>
@@ -53,6 +57,12 @@ static int acpi_ac_resume(struct device
#endif
static SIMPLE_DEV_PM_OPS(acpi_ac_pm, NULL, acpi_ac_resume);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+extern struct proc_dir_entry *acpi_lock_ac_dir(void);
+extern void *acpi_unlock_ac_dir(struct proc_dir_entry *acpi_ac_dir);
+#endif
+
+
static int ac_sleep_before_get_state_ms;
static int ac_only;
@@ -132,6 +142,74 @@ static enum power_supply_property ac_pro
POWER_SUPPLY_PROP_ONLINE,
};
+#ifdef CONFIG_ACPI_PROCFS_POWER
+/* proc I/F */
+static struct proc_dir_entry *acpi_ac_dir;
+
+static int acpi_ac_seq_show(struct seq_file *seq, void *offset)
+{
+ struct acpi_ac *ac = seq->private;
+
+
+ if (!ac)
+ return 0;
+
+ if (acpi_ac_get_state(ac)) {
+ seq_puts(seq, "ERROR: Unable to read AC Adapter state\n");
+ return 0;
+ }
+
+ seq_puts(seq, "state: ");
+ switch (ac->state) {
+ case ACPI_AC_STATUS_OFFLINE:
+ seq_puts(seq, "off-line\n");
+ break;
+ case ACPI_AC_STATUS_ONLINE:
+ seq_puts(seq, "on-line\n");
+ break;
+ default:
+ seq_puts(seq, "unknown\n");
+ break;
+ }
+
+ return 0;
+}
+
+static int acpi_ac_add_fs(struct acpi_ac *ac)
+{
+ struct proc_dir_entry *entry = NULL;
+
+ printk(KERN_WARNING PREFIX "Deprecated procfs I/F for AC is loaded,"
+ " please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
+ if (!acpi_device_dir(ac->device)) {
+ acpi_device_dir(ac->device) =
+ proc_mkdir(acpi_device_bid(ac->device), acpi_ac_dir);
+ if (!acpi_device_dir(ac->device))
+ return -ENODEV;
+ }
+
+ /* 'state' [R] */
+ entry = proc_create_single_data(ACPI_AC_FILE_STATE, S_IRUGO,
+ acpi_device_dir(ac->device), acpi_ac_seq_show, ac);
+ if (!entry)
+ return -ENODEV;
+ return 0;
+}
+
+static int acpi_ac_remove_fs(struct acpi_ac *ac)
+{
+
+ if (acpi_device_dir(ac->device)) {
+ remove_proc_entry(ACPI_AC_FILE_STATE,
+ acpi_device_dir(ac->device));
+ remove_proc_entry(acpi_device_bid(ac->device), acpi_ac_dir);
+ acpi_device_dir(ac->device) = NULL;
+ }
+
+ return 0;
+}
+#endif
+
/* Driver Model */
static void acpi_ac_notify(struct acpi_device *device, u32 event)
{
@@ -245,6 +323,11 @@ static int acpi_ac_add(struct acpi_devic
psy_cfg.drv_data = ac;
ac->charger_desc.name = acpi_device_bid(device);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ result = acpi_ac_add_fs(ac);
+ if (result)
+ goto end;
+#endif
ac->charger_desc.type = POWER_SUPPLY_TYPE_MAINS;
ac->charger_desc.properties = ac_props;
ac->charger_desc.num_properties = ARRAY_SIZE(ac_props);
@@ -262,8 +345,12 @@ static int acpi_ac_add(struct acpi_devic
ac->battery_nb.notifier_call = acpi_ac_battery_notify;
register_acpi_notifier(&ac->battery_nb);
end:
- if (result)
+ if (result) {
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ acpi_ac_remove_fs(ac);
+#endif
kfree(ac);
+ }
return result;
}
@@ -305,6 +392,10 @@ static int acpi_ac_remove(struct acpi_de
power_supply_unregister(ac->charger);
unregister_acpi_notifier(&ac->battery_nb);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ acpi_ac_remove_fs(ac);
+#endif
+
kfree(ac);
return 0;
@@ -322,9 +413,19 @@ static int __init acpi_ac_init(void)
dmi_check_system(ac_dmi_table);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ acpi_ac_dir = acpi_lock_ac_dir();
+ if (!acpi_ac_dir)
+ return -ENODEV;
+#endif
+
result = acpi_bus_register_driver(&acpi_ac_driver);
- if (result < 0)
+ if (result < 0) {
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ acpi_unlock_ac_dir(acpi_ac_dir);
+#endif
return -ENODEV;
+ }
return 0;
}
@@ -332,6 +433,9 @@ static int __init acpi_ac_init(void)
static void __exit acpi_ac_exit(void)
{
acpi_bus_unregister_driver(&acpi_ac_driver);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ acpi_unlock_ac_dir(acpi_ac_dir);
+#endif
}
module_init(acpi_ac_init);
module_exit(acpi_ac_exit);
Index: linux-pm/drivers/acpi/battery.c
===================================================================
--- linux-pm.orig/drivers/acpi/battery.c
+++ linux-pm/drivers/acpi/battery.c
@@ -24,6 +24,12 @@
#include <asm/unaligned.h>
+#ifdef CONFIG_ACPI_PROCFS_POWER
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#endif
+
#include <linux/acpi.h>
#include <linux/power_supply.h>
@@ -57,6 +63,11 @@ static unsigned int cache_time = 1000;
module_param(cache_time, uint, 0644);
MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
+#ifdef CONFIG_ACPI_PROCFS_POWER
+extern struct proc_dir_entry *acpi_lock_battery_dir(void);
+extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
+#endif
+
static const struct acpi_device_id battery_device_ids[] = {
{"PNP0C0A", 0},
{"", 0},
@@ -1018,6 +1029,223 @@ static void acpi_battery_refresh(struct
sysfs_add_battery(battery);
}
+#ifdef CONFIG_ACPI_PROCFS_POWER
+/* proc I/F */
+static struct proc_dir_entry *acpi_battery_dir;
+
+static const char *acpi_battery_units(const struct acpi_battery *battery)
+{
+ return (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) ?
+ "mA" : "mW";
+}
+
+static int acpi_battery_info_proc_show(struct seq_file *seq, void *offset)
+{
+ struct acpi_battery *battery = seq->private;
+ int result = acpi_battery_update(battery, false);
+
+ if (result)
+ goto end;
+
+ seq_printf(seq, "present: %s\n",
+ acpi_battery_present(battery) ? "yes" : "no");
+ if (!acpi_battery_present(battery))
+ goto end;
+ if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+ seq_printf(seq, "design capacity: unknown\n");
+ else
+ seq_printf(seq, "design capacity: %d %sh\n",
+ battery->design_capacity,
+ acpi_battery_units(battery));
+
+ if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+ seq_printf(seq, "last full capacity: unknown\n");
+ else
+ seq_printf(seq, "last full capacity: %d %sh\n",
+ battery->full_charge_capacity,
+ acpi_battery_units(battery));
+
+ seq_printf(seq, "battery technology: %srechargeable\n",
+ battery->technology ? "" : "non-");
+
+ if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
+ seq_printf(seq, "design voltage: unknown\n");
+ else
+ seq_printf(seq, "design voltage: %d mV\n",
+ battery->design_voltage);
+ seq_printf(seq, "design capacity warning: %d %sh\n",
+ battery->design_capacity_warning,
+ acpi_battery_units(battery));
+ seq_printf(seq, "design capacity low: %d %sh\n",
+ battery->design_capacity_low,
+ acpi_battery_units(battery));
+ seq_printf(seq, "cycle count: %i\n", battery->cycle_count);
+ seq_printf(seq, "capacity granularity 1: %d %sh\n",
+ battery->capacity_granularity_1,
+ acpi_battery_units(battery));
+ seq_printf(seq, "capacity granularity 2: %d %sh\n",
+ battery->capacity_granularity_2,
+ acpi_battery_units(battery));
+ seq_printf(seq, "model number: %s\n", battery->model_number);
+ seq_printf(seq, "serial number: %s\n", battery->serial_number);
+ seq_printf(seq, "battery type: %s\n", battery->type);
+ seq_printf(seq, "OEM info: %s\n", battery->oem_info);
+ end:
+ if (result)
+ seq_printf(seq, "ERROR: Unable to read battery info\n");
+ return result;
+}
+
+static int acpi_battery_state_proc_show(struct seq_file *seq, void *offset)
+{
+ struct acpi_battery *battery = seq->private;
+ int result = acpi_battery_update(battery, false);
+
+ if (result)
+ goto end;
+
+ seq_printf(seq, "present: %s\n",
+ acpi_battery_present(battery) ? "yes" : "no");
+ if (!acpi_battery_present(battery))
+ goto end;
+
+ seq_printf(seq, "capacity state: %s\n",
+ (battery->state & 0x04) ? "critical" : "ok");
+ if ((battery->state & 0x01) && (battery->state & 0x02))
+ seq_printf(seq,
+ "charging state: charging/discharging\n");
+ else if (battery->state & 0x01)
+ seq_printf(seq, "charging state: discharging\n");
+ else if (battery->state & 0x02)
+ seq_printf(seq, "charging state: charging\n");
+ else
+ seq_printf(seq, "charging state: charged\n");
+
+ if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
+ seq_printf(seq, "present rate: unknown\n");
+ else
+ seq_printf(seq, "present rate: %d %s\n",
+ battery->rate_now, acpi_battery_units(battery));
+
+ if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
+ seq_printf(seq, "remaining capacity: unknown\n");
+ else
+ seq_printf(seq, "remaining capacity: %d %sh\n",
+ battery->capacity_now, acpi_battery_units(battery));
+ if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
+ seq_printf(seq, "present voltage: unknown\n");
+ else
+ seq_printf(seq, "present voltage: %d mV\n",
+ battery->voltage_now);
+ end:
+ if (result)
+ seq_printf(seq, "ERROR: Unable to read battery state\n");
+
+ return result;
+}
+
+static int acpi_battery_alarm_proc_show(struct seq_file *seq, void *offset)
+{
+ struct acpi_battery *battery = seq->private;
+ int result = acpi_battery_update(battery, false);
+
+ if (result)
+ goto end;
+
+ if (!acpi_battery_present(battery)) {
+ seq_printf(seq, "present: no\n");
+ goto end;
+ }
+ seq_printf(seq, "alarm: ");
+ if (battery->alarm) {
+ seq_printf(seq, "%u %sh\n", battery->alarm,
+ acpi_battery_units(battery));
+ } else {
+ seq_printf(seq, "unsupported\n");
+ }
+ end:
+ if (result)
+ seq_printf(seq, "ERROR: Unable to read battery alarm\n");
+ return result;
+}
+
+static ssize_t acpi_battery_write_alarm(struct file *file,
+ const char __user * buffer,
+ size_t count, loff_t * ppos)
+{
+ int result = 0;
+ char alarm_string[12] = { '\0' };
+ struct seq_file *m = file->private_data;
+ struct acpi_battery *battery = m->private;
+
+ if (!battery || (count > sizeof(alarm_string) - 1))
+ return -EINVAL;
+ if (!acpi_battery_present(battery)) {
+ result = -ENODEV;
+ goto end;
+ }
+ if (copy_from_user(alarm_string, buffer, count)) {
+ result = -EFAULT;
+ goto end;
+ }
+ alarm_string[count] = '\0';
+ if (kstrtoint(alarm_string, 0, &battery->alarm)) {
+ result = -EINVAL;
+ goto end;
+ }
+ result = acpi_battery_set_alarm(battery);
+ end:
+ if (result)
+ return result;
+ return count;
+}
+
+static int acpi_battery_alarm_proc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, acpi_battery_alarm_proc_show, PDE_DATA(inode));
+}
+
+static const struct proc_ops acpi_battery_alarm_proc_ops = {
+ .proc_open = acpi_battery_alarm_proc_open,
+ .proc_read = seq_read,
+ .proc_write = acpi_battery_write_alarm,
+ .proc_lseek = seq_lseek,
+ .proc_release = single_release,
+};
+
+static int acpi_battery_add_fs(struct acpi_device *device)
+{
+ pr_warn(PREFIX "Deprecated procfs I/F for battery is loaded, please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
+ if (!acpi_device_dir(device)) {
+ acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
+ acpi_battery_dir);
+ if (!acpi_device_dir(device))
+ return -ENODEV;
+ }
+
+ if (!proc_create_single_data("info", S_IRUGO, acpi_device_dir(device),
+ acpi_battery_info_proc_show, acpi_driver_data(device)))
+ return -ENODEV;
+ if (!proc_create_single_data("state", S_IRUGO, acpi_device_dir(device),
+ acpi_battery_state_proc_show, acpi_driver_data(device)))
+ return -ENODEV;
+ if (!proc_create_data("alarm", S_IFREG | S_IRUGO | S_IWUSR,
+ acpi_device_dir(device), &acpi_battery_alarm_proc_ops,
+ acpi_driver_data(device)))
+ return -ENODEV;
+ return 0;
+}
+
+static void acpi_battery_remove_fs(struct acpi_device *device)
+{
+ if (!acpi_device_dir(device))
+ return;
+ remove_proc_subtree(acpi_device_bid(device), acpi_battery_dir);
+ acpi_device_dir(device) = NULL;
+}
+
+#endif
+
/* Driver Interface */
static void acpi_battery_notify(struct acpi_device *device, u32 event)
{
@@ -1200,6 +1428,14 @@ static int acpi_battery_add(struct acpi_
if (result)
goto fail;
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ result = acpi_battery_add_fs(device);
+ if (result) {
+ acpi_battery_remove_fs(device);
+ goto fail;
+ }
+#endif
+
pr_info("Slot [%s] (battery %s)\n", acpi_device_bid(device),
device->status.battery_present ? "present" : "absent");
@@ -1227,6 +1463,9 @@ static int acpi_battery_remove(struct ac
device_init_wakeup(&device->dev, 0);
battery = acpi_driver_data(device);
unregister_pm_notifier(&battery->pm_nb);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ acpi_battery_remove_fs(device);
+#endif
sysfs_remove_battery(battery);
mutex_destroy(&battery->lock);
mutex_destroy(&battery->sysfs_lock);
@@ -1279,7 +1518,16 @@ static void __init acpi_battery_init_asy
dmi_check_system(bat_dmi_table);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ acpi_battery_dir = acpi_lock_battery_dir();
+ if (!acpi_battery_dir)
+ return;
+#endif
result = acpi_bus_register_driver(&acpi_battery_driver);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ if (result < 0)
+ acpi_unlock_battery_dir(acpi_battery_dir);
+#endif
battery_driver_registered = (result == 0);
}
@@ -1299,6 +1547,10 @@ static void __exit acpi_battery_exit(voi
acpi_bus_unregister_driver(&acpi_battery_driver);
battery_hook_exit();
}
+#ifdef CONFIG_ACPI_PROCFS_POWER
+ if (acpi_battery_dir)
+ acpi_unlock_battery_dir(acpi_battery_dir);
+#endif
}
module_init(acpi_battery_init);
