lkml.org 
[lkml]   [2022]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 2/2] hwmon: acpi_power_meter: convert to hwmon_device_register_with_info
Le Sun, May 15, 2022 at 05:29:54PM -0700, Guenter Roeck a écrit :
> On 5/15/22 12:36, LABBE Corentin wrote:
> > Le Wed, May 11, 2022 at 07:10:29PM -0700, Guenter Roeck a écrit :
> >> Corentin,
> >>
> >> On 5/8/22 23:30, Corentin Labbe wrote:
> >>> Booting lead to a hwmon_device_register() is deprecated. Please convert the driver to use hwmon_device_register_with_info().
> >>> So let's convert the driver to use hwmon_device_register_with_info().
> >>>
> >>> Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
> >>> ---
> >> [ ... ]
> >>
> >>> @@ -836,20 +740,20 @@ static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
> >>> if (res)
> >>> break;
> >>>
> >>> - remove_attrs(resource);
> >>> + remove_domain_devices(resource);
> >>> setup_attrs(resource);
> >>
> >> Zhang Rui found an interesting problem with this code:
> >> It needs a call to sysfs_update_groups(hwmon_dev->groups)
> >> to update sysfs attribute visibility, probably between
> >> remove_domain_devices() and setup_attrs().
> >>
> >>> break;
> >>> case METER_NOTIFY_TRIP:
> >>> - sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
> >>> + hwmon_notify_event(&device->dev, hwmon_power, hwmon_power_average, 0);
> >>
> >> ... which makes realize: The notification device should be the hwmon device.
> >> That would be resource->hwmon_dev, not the acpi device.
> >>
> >
> > Hello
> >
> > Since my hardware lacks capabilities testing this, I have emulated it on qemu:
> > https://github.com/montjoie/qemu/commit/320f2ddacb954ab308ef699f66fca6313f75bc2b
> >
> > I have added a custom ACPI _DBX method for triggering some ACPI state change. (like config change, like enabling CAP).
> >
> > For testing config change I have tried lot of way:
> > res = read_capabilities(resource);
> > @@ -742,18 +758,22 @@ static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
> >
> > remove_domain_devices(resource);
> > setup_attrs(resource);
> > + res = sysfs_update_groups(&resource->hwmon_dev->kobj, acpi_power_groups);
> > + res = sysfs_update_groups(&resource->acpi_dev->dev.kobj, acpi_power_groups);
> > + res = hwmon_notify_event(resource->hwmon_dev, hwmon_power, hwmon_power_cap, 0);
> > + res = hwmon_notify_event(resource->hwmon_dev, hwmon_power, hwmon_power_average, 0);
>
> Did you add a debug log here ?

Yes I added debug log to check what is called.

>
> acpi_power_groups would be the wrong parameter for sysfs_update_groups().
> It would have to be resource->hwmon_dev->groups.
>

Even with that, no call to is_visible:
@@ -742,18 +758,22 @@ static void acpi_power_meter_notify(struct acpi_device *device, u32 event)

remove_domain_devices(resource);
setup_attrs(resource);
+ res = sysfs_update_groups(&resource->hwmon_dev->kobj, resource->hwmon_dev->groups);
+ res = sysfs_update_groups(&resource->acpi_dev->dev.kobj, resource->hwmon_dev->groups);
+ res = hwmon_notify_event(resource->hwmon_dev, hwmon_power, hwmon_power_cap, 0);
+ res = hwmon_notify_event(resource->hwmon_dev, hwmon_power, hwmon_power_average, 0);
break;

I checked drivers/hwmon/hwmon.c is seems that is_visible is only called by gen_attr/gen_attrs which is only called by __hwmon_create_attrs and then by registers functions.
So perhaps it explain why it is never called.

\
 
 \ /
  Last update: 2022-05-16 08:22    [W:0.169 / U:0.284 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site