(no subject)

[Paul Marques Mota]

From: Paul Marques Mota <paul@marquesmota.pt>
To: HARDWARE MONITORING <linux-hwmon@vger.kernel.org>
Date: Thu, 7 Dec 2017 20:04:22 +0000
Subject: [PATCH] add stack trace to deprecated hwmon_device_register()

Hi,

hwmon_device_register() in drivers/hwmon/hwmon.c prints the unhelpful
message below on my machine:

(NULL device *): hwmon_device_register() is deprecated. Please convert the driver to use hwmon_device_register_with_info().

Therefore, this patch dumps the stack at that point. In my case it is
then obvious in the resulting dmesg, available at

http://www.marquesmota.pt/dmesg.txt

that thermal_add_hwmon_sysfs() in drivers/thermal/thermal_hwmon.c needs
to be converted to the new API.

This patch is against 4.15.0-rc2
I believe it is also needed in Bugzilla bug #195843
https://bugzilla.kernel.org/show_bug.cgi?id=195843

Signed-off-by: Paul Marques Mota<paul@marquesmota.pt>

---
 drivers/hwmon/hwmon.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index c9790e2c3440..31719ce4a681 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -702,6 +702,7 @@ struct device *hwmon_device_register(struct device *dev)
 {
 	dev_warn(dev,
 		 "hwmon_device_register() is deprecated. Please convert the driver to use hwmon_device_register_with_info().\n");
+	dump_stack();
 
 	return __hwmon_device_register(dev, NULL, NULL, NULL, NULL);
 }
-- 
2.15.1

Re: your mail

[Guenter Roeck]

On Thu, Dec 07, 2017 at 09:32:01PM +0000, Paul Marques Mota wrote:
> From: Paul Marques Mota <paul@marquesmota.pt>
> To: HARDWARE MONITORING <linux-hwmon@vger.kernel.org>
> Date: Thu, 7 Dec 2017 20:04:22 +0000
> Subject: [PATCH] add stack trace to deprecated hwmon_device_register()
> 
> Hi,
> 
> hwmon_device_register() in drivers/hwmon/hwmon.c prints the unhelpful
> message below on my machine:
> 
> (NULL device *): hwmon_device_register() is deprecated. Please convert the driver to use hwmon_device_register_with_info().
> 
> Therefore, this patch dumps the stack at that point. In my case it is
> then obvious in the resulting dmesg, available at
> 
> http://www.marquesmota.pt/dmesg.txt
> 
> that thermal_add_hwmon_sysfs() in drivers/thermal/thermal_hwmon.c needs
> to be converted to the new API.
> 
> This patch is against 4.15.0-rc2
> I believe it is also needed in Bugzilla bug #195843
> https://bugzilla.kernel.org/show_bug.cgi?id=195843
> 
> Signed-off-by: Paul Marques Mota<paul@marquesmota.pt>

Nack, this is not needed. The thermal subsystem is the only subsystem
which doesn't pass a device pointer, and I don't want to have logs
clogged up with unnecessary tracebacks because of it.

If it wasn't for thermal, I would actually let hwmon registrations with
NULL device pointer fail completely. Unfortunately there is no easy way
to convert the thermal subsystem to use hwmon_device_register_with_info(),
since even though thermal_zone_device_register() registers a thermal zone
device, it does not have a notion of 'struct device *'.

Maybe someone can step in and convert the thermal code to use
hwmon_device_register_with_groups(). That doesn't really solve the problem,
but at least the symptom would be gone, and the thermal code would be
a little cleaner.

Guenter

Re: your mail

[Paul Marques Mota]

Le 07/12/2017 à 23:34, Guenter Roeck a écrit :

> Nack, this is not needed.

Ok, thank you for the quick answer.

> Guenter

Regards,

-- 
Paul