From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1191C243969; Thu, 4 Sep 2025 10:29:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756981783; cv=none; b=WJMLmDLG9shE15xaT1EH9gi7UUFo3Drd0WeTo0PKwkgQpkuJnL6gKiXprDEhFcRb/vXNtMcD0hFuNRzB5Ax0teb33tBZIm8KYX0Ma/NpQvKt2pxY2/e2E5rX3LucDsWq/1MbNksWaRtI39s4aDioZKcvEuTJU5UyKzYr7VJKPfg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756981783; c=relaxed/simple; bh=DNrVqVw2HFa43h6zUP2Pkf3Y1kZQlXTxFVZ+H36A3c8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ZJ5nrNybF7fxi49AXLbS2WczpilRGOJJtDExUTgW3U2e2XDwKItqkBVWjt7RxdEde38EKe7e++De6CdEpvEVjqc2iRSWFObQATiY/OZT9RUwUAARRaKu8k5C7r66OvsipT2PW5AKarMClyiHBrCXrZuoOC464b4Qi4Mxnu9KwUI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HeRQflD1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HeRQflD1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89731C4CEF0; Thu, 4 Sep 2025 10:29:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756981782; bh=DNrVqVw2HFa43h6zUP2Pkf3Y1kZQlXTxFVZ+H36A3c8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=HeRQflD1lfGHVGsCwxziyULGLtgsyRXMJOjkx/eL0QGVbZE5E7HMMcEQuATaR4fYf bETsR2bi5BHiWvRmXfjATsm4/PrSvMabQGijybh9z++Ms0oRsUY4sq2oh5szuMsM7c 6lgpZ3UYs3O4vUadnc4DWz/hrSg6kocAvJfsh3O/liXCkuODYd8+4OsO+kyutUVhFF 7EOIPzpkYdDQq8JAgVq3zTQjXiDW9E2GjX6KvF/U0mxpX+H5vt32Ez7jkgzXRcQtA3 XqRbFEay9vkR/uWQ5DVklkSnBuPluNEZ3wwkghioMH9nN1CTZuRO1zCE83bMZZVhZP v00Mn7YCEBCIw== Message-ID: <691f72aa-6d3e-47a1-9efe-a5f7a61ecb72@kernel.org> Date: Thu, 4 Sep 2025 12:29:38 +0200 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] dt-bindings: leds: add generic LED consumer documentation To: Krzysztof Kozlowski , Aleksandrs Vinarskis Cc: robh@kernel.org, bryan.odonoghue@linaro.org, conor+dt@kernel.org, devicetree@vger.kernel.org, krzk+dt@kernel.org, lee@kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, pavel@kernel.org References: <20250902182114.GA965402-robh@kernel.org> <20250903235615.134520-1-alex@vinarskis.com> <20250904-brave-zippy-quoll-fcb054@kuoka> From: Hans de Goede Content-Language: en-US, nl In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Krzysztof, On 4-Sep-25 11:45 AM, Krzysztof Kozlowski wrote: > On 04/09/2025 09:26, Hans de Goede wrote: >>>>>> +maintainers: >>>>>> + - Aleksandrs Vinarskis >>>>>> + >>>>>> +description: >>>>>> + Some LED defined in DT are required by other DT consumers, for example >>>>>> + v4l2 subnode may require privacy or flash LED. >>>>>> + >>>>>> + Document LED properties that its consumers may define. >>>>> >>>>> We already have the trigger-source binding for "attaching" LEDs to >>>>> devices. Why does that not work here? >>>> >>>> I have not actually considered this, as the existing privacy-led solution >>>> from the original series is not trigger based. At least one of the reasons >>>> for that is that trigger source can be rather easily altered from user >>>> space, which would've been bad for this use case. If v4l2 acquires control >>>> over the LED it actually removes triggers and disables sysfs on that LED. >>> >>> So does that mean that v4l2 solves the problem of "trigger source can be >>> rather easily altered from user space"? >> >> Yes, currently the v4l2-core already does: > > Thanks, I understand that it solves the problem described in the patch, > so the patch can be dropped. I'm a bit confused now, do you mean that this dt-bindings patch can be dropped ? The existing v4l2-core code solves getting the privacy-LED on ACPI/x86_64, on DT there is no official bindings-docs for directly getting a LED with led_get() AFAICT and I believe that having a binding is mandatory before we just start adding leds and led-names properties to DT nodes for sensors ? Maybe for v2 of this patch-set Aleksanders should also add a patch actually using the new binding in a dts file to make clear that the intent is to also start using privacy-LEDs in the same way on DT systems ? Regards, Hans