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Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <7c38ad68-49cb-0f8a-18a4-fa78f0429bdd@roeck-us.net>
Date:   Fri, 25 Nov 2022 17:46:40 -0800
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Subject: Re: [PATCH] watchdog: Report firmware_version in sysfs
Content-Language: en-US
To:     =?UTF-8?Q?Thomas_Wei=c3=9fschuh?= <linux@weissschuh.net>
Cc:     Wim Van Sebroeck <wim@linux-watchdog.org>,
        linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20221125222315.4925-1-linux@weissschuh.net>
 <da94449e-d250-1b44-0e72-f951b73b1946@roeck-us.net>
 <ddd1ea7b-0be7-4c16-a5ac-56516f955ef9@t-8ch.de>
From:   Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <ddd1ea7b-0be7-4c16-a5ac-56516f955ef9@t-8ch.de>
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On 11/25/22 17:00, Thomas Weißschuh wrote:
> On 2022-11-25 16:37-0800, Guenter Roeck wrote:
>> On 11/25/22 14:23, Thomas Weißschuh wrote:
>>> This synchronizes the information reported by ioctl and sysfs.
>>> The mismatch is confusing because "wdctl" from util-linux uses the ioctl
>>> when used with root privileges and sysfs without.
>>>
>>> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
>>>
>>> ---
>>>
>>> Userspace implementation:
>>>
>>> https://github.com/util-linux/util-linux/pull/1927
>>> ---
>>>    drivers/watchdog/watchdog_dev.c | 10 ++++++++++
>>>    1 file changed, 10 insertions(+)
>>>
>>> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
>>> index 55574ed42504..88c76e27873c 100644
>>> --- a/drivers/watchdog/watchdog_dev.c
>>> +++ b/drivers/watchdog/watchdog_dev.c
>>> @@ -555,6 +555,15 @@ static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
>>>    }
>>>    static DEVICE_ATTR_RO(identity);
>>> +static ssize_t firmware_version_show(struct device *dev, struct device_attribute *attr,
>>> +				     char *buf)
>>> +{
>>> +	struct watchdog_device *wdd = dev_get_drvdata(dev);
>>> +
>>> +	return sysfs_emit(buf, "%d\n", wdd->info->firmware_version);
>>> +}
>>> +static DEVICE_ATTR_RO(firmware_version);
>>> +
>>>    static ssize_t state_show(struct device *dev, struct device_attribute *attr,
>>>    				char *buf)
>>>    {
>>> @@ -618,6 +627,7 @@ static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
>>>    static struct attribute *wdt_attrs[] = {
>>>    	&dev_attr_state.attr,
>>>    	&dev_attr_identity.attr,
>>> +	&dev_attr_firmware_version.attr,
>>>    	&dev_attr_timeout.attr,
>>>    	&dev_attr_min_timeout.attr,
>>>    	&dev_attr_max_timeout.attr,
>>>
>>> base-commit: 0b1dcc2cf55ae6523c6fbd0d741b3ac28c9f4536
>>
>> I think this conflicts with drivers/watchdog/ziirave_wdt.c which generates its own
>> firmnware_version attribute.
> 
> Indeed, thanks for the catch.
> 
> We probably can't change the attribute from ziirave_wdt, which is a bit
> unfortunate as "firmware_version" would nicely match the name from
> "struct watchdog_info".
> 
> How about "fw_version"?
> 

I don't have a better idea. Go for it.

Guenter

> That would match the naming of sysfs attributes from a bunch of other
> subsystems.
> 
> And obviously an addition to Documentation/ABI/testing/sysfs-class-watchdog is
> also missing from the patch.
> I'll add it in v2.
> 
> Thomas