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Message-ID: <84de2a98-3051-82ec-6686-ef4161535d23@redhat.com>
Date:   Thu, 17 Feb 2022 17:28:32 +0100
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Subject: Re: [PATCH] platform/x86: Add Steam Deck driver
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To:     Andrey Smirnov <andrew.smirnov@gmail.com>,
        =?UTF-8?Q?Barnab=c3=a1s_P=c5=91cze?= <pobrn@protonmail.com>
Cc:     platform-driver-x86@vger.kernel.org,
        Mark Gross <markgross@kernel.org>,
        Jean Delvare <jdelvare@suse.com>,
        Guenter Roeck <linux@roeck-us.net>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-hwmon@vger.kernel.org
References: <20220206022023.376142-1-andrew.smirnov@gmail.com>
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 <CAHQ1cqF5HCJVsmyMHMxU85Uwv_Yd8qoAUVMz7R_zo0S9_pFZfg@mail.gmail.com>
From:   Hans de Goede <hdegoede@redhat.com>
In-Reply-To: <CAHQ1cqF5HCJVsmyMHMxU85Uwv_Yd8qoAUVMz7R_zo0S9_pFZfg@mail.gmail.com>
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Hi,

On 2/13/22 00:30, Andrey Smirnov wrote:

<snip>

>>> +static struct attribute *steamdeck_attributes[] = {
>>> +     &dev_attr_target_cpu_temp.attr,
>>> +     &dev_attr_gain.attr,
>>> +     &dev_attr_ramp_rate.attr,
>>> +     &dev_attr_hysteresis.attr,
>>> +     &dev_attr_maximum_battery_charge_rate.attr,
>>> +     &dev_attr_recalculate.attr,
>>> +     &dev_attr_power_cycle_display.attr,
>>> +
>>> +     &dev_attr_led_brightness.attr,
>>
>> Have you considered using a led class device instead? I think that should
>> work even without the ability to query the brightness.
>>
> 
> Not very seriously. Will take another look.
> 
>>
>>> +     &dev_attr_content_adaptive_brightness.attr,
>>> +     &dev_attr_gamma_set.attr,
>>> +     &dev_attr_display_brightness.attr,
>>
>> Have you considered using a backlight class device?
>>
> 
> Ditto.

Note that for both of these I would go a bit further then
"have you considered?". Since you are implementing standardized
userspace APIs here you *must* use the shared subsystem code
for registering a LED resp backlight class device here so that
everything is guaranteed to behave as expected by userspace.

Regards,

Hans