Re: [PATCH] 2.6.24-rc2: fix oops in ACPI battery removal

[Alexey Starikovskiy <astarikovskiy@suse.de>]

Andrey,

Fix already exists. It already went up to Len's tree.

Regards,
Alex.

Andrey Borzenkov wrote:
> Alexey, this fixes my patch that went into -rc2. Sorry for Oops.
> 
> Subject: [PATCH] 2.6.24-rc2: do not unregister power_supply in sysfs ->show method
> From: Andrey Borzenkov <arvidjaar@mail.ru>
> 
> Currently unplugging battery oopses with call stack:
> 
> [ 2245.375393]  [<c010488a>] show_trace_log_lvl+0x1a/0x30
> [ 2245.375570]  [<c0104949>] show_stack_log_lvl+0xa9/0xd0
> [ 2245.375732]  [<c0104a36>] show_registers+0xc6/0x1c0
> [ 2245.375884]  [<c0104c21>] die+0xf1/0x200
> [ 2245.376014]  [<c02d2a58>] do_page_fault+0x198/0x690
> [ 2245.376207]  [<c02d1522>] error_code+0x6a/0x70
> [ 2245.376366]  [<c0243c20>] device_del+0x20/0x280
> [ 2245.376530]  [<c0243e8b>] device_unregister+0xb/0x20
> [ 2245.376686]  [<dfd7401a>] power_supply_unregister+0x1a/0x20 [power_supply]
> [ 2245.376911]  [<dfd5f035>] sysfs_remove_battery+0x1f/0x22 [battery]
> [ 2245.382969]  [<dfd5f1e6>] acpi_battery_update+0x42/0x293 [battery]
> [ 2245.388862]  [<dfd5f5f5>] acpi_battery_get_property+0x34/0x16e [battery]
> [ 2245.394770]  [<dfd74368>] power_supply_show_property+0x38/0x130 [power_supply]
> [ 2245.400733]  [<dfd746f1>] power_supply_uevent+0x111/0x1c0 [power_supply]
> [ 2245.406745]  [<c0244559>] dev_uevent+0x99/0x100
> [ 2245.412744]  [<c01d37ff>] kobject_uevent_env+0x17f/0x3c0
> [ 2245.418768]  [<c01d3a4a>] kobject_uevent+0xa/0x10
> [ 2245.424732]  [<c0243da3>] device_del+0x1a3/0x280
> [ 2245.430683]  [<c0243e8b>] device_unregister+0xb/0x20
> [ 2245.436632]  [<dfd7401a>] power_supply_unregister+0x1a/0x20 [power_supply]
> [ 2245.442670]  [<dfd5f035>] sysfs_remove_battery+0x1f/0x22 [battery]
> [ 2245.448790]  [<dfd5f1e6>] acpi_battery_update+0x42/0x293 [battery]
> [ 2245.454874]  [<dfd5f7ad>] acpi_battery_notify+0x1e/0x69 [battery]
> [ 2245.460957]  [<c02086cd>] acpi_ev_notify_dispatch+0x4c/0x57
> [ 2245.467077]  [<c0200d54>] acpi_os_execute_notify+0x24/0x2f
> [ 2245.473167]  [<c012a431>] run_workqueue+0x161/0x1e0
> [ 2245.479289]  [<c012ae5b>] worker_thread+0x8b/0xf0
> [ 2245.485279]  [<c012e0b2>] kthread+0x42/0x70
> [ 2245.491068]  [<c01044e3>] kernel_thread_helper+0x7/0x14
> 
> Do not try to (un-)register sysfs in acpi_battery_update - instead, do
> it only on battery add or in notification handler.
> 
> On the way fix battery removal (reset device to NULL) and use proper
> interface for sending change event (power_supply_changed) instead of
> doing it directly.
> 
> Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru>
> 
> ---
> 
>  drivers/acpi/battery.c |   18 +++++++++---------
>  1 files changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> index 1905b88..2810a9b 100644
> --- a/drivers/acpi/battery.c
> +++ b/drivers/acpi/battery.c
> @@ -457,6 +457,7 @@ static void sysfs_remove_battery(struct acpi_battery *battery)
>  		return;
>  	device_remove_file(battery->bat.dev, &alarm_attr);
>  	power_supply_unregister(&battery->bat);
> +	battery->bat.dev = NULL;
>  }
>  
>  static int acpi_battery_update(struct acpi_battery *battery)
> @@ -464,12 +465,6 @@ static int acpi_battery_update(struct acpi_battery *battery)
>  	int result = acpi_battery_get_status(battery);
>  	if (result)
>  		return result;
> -	if (!acpi_battery_present(battery)) {
> -		sysfs_remove_battery(battery);
> -		return 0;
> -	}
> -	if (!battery->bat.dev)
> -		sysfs_add_battery(battery);
>  	return acpi_battery_get_state(battery);
>  }
>  
> @@ -758,14 +753,17 @@ static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
>  		return;
>  	device = battery->device;
>  	acpi_battery_update(battery);
> +	if (!acpi_battery_present(battery))
> +		sysfs_remove_battery(battery);
> +	else if (!battery->bat.dev)
> +		sysfs_add_battery(battery);
> +	else
> +		power_supply_changed(&battery->bat);
>  	acpi_bus_generate_proc_event(device, event,
>  				     acpi_battery_present(battery));
>  	acpi_bus_generate_netlink_event(device->pnp.device_class,
>  					device->dev.bus_id, event,
>  					acpi_battery_present(battery));
> -	/* acpi_batter_update could remove power_supply object */
> -	if (battery->bat.dev)
> -		kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE);
>  }
>  
>  static int acpi_battery_add(struct acpi_device *device)
> @@ -784,6 +782,8 @@ static int acpi_battery_add(struct acpi_device *device)
>  	acpi_driver_data(device) = battery;
>  	mutex_init(&battery->lock);
>  	acpi_battery_update(battery);
> +	if (acpi_battery_present(battery))
> +		sysfs_add_battery(battery);
>  #ifdef CONFIG_ACPI_PROCFS
>  	result = acpi_battery_add_fs(device);
>  	if (result)