From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (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 8D9EC34BA3B; Tue, 30 Sep 2025 11:34:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759232069; cv=none; b=hp9m7lCesB3hbuLLzRLPBbLLNTiMIR9dViWr0Abo9gB2GfaLTRwE9nc4xCISG/sc0qo2PfwdpZHJpmCJjCLYheDGlGPDh1Po/EQ+CE4SmgrEMyNfErYYYEOCzOU7/HW+W17FD5g+O5nvpFEwhUkrHlCogHLYS0RWiqg1GFN3Ri0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759232069; c=relaxed/simple; bh=tiHFk+xnP8SCA8zL96xKjLYHlIM3mrrw6V0YZnBkr44=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=phbFr9gCmrwLwHNpQMiXHfTu3CvY0fcYWKIu3/KOTguCKAYpgakp2mHviNANmAm44fx63+wwuPPH32OQs3YlCeluqWEEcW/hIHfOO15LYrVv1VbcJrwyPtzo7VhpoywNbFBha2mOUsZP5ZVRJ2mm6t3esk0DrGje+axViXu699Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=aLvaKjQc; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="aLvaKjQc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1759232065; bh=tiHFk+xnP8SCA8zL96xKjLYHlIM3mrrw6V0YZnBkr44=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=aLvaKjQc2v07qJGvKM+cMa88Ljf8faYwGdWNauchDkYGAEKudftAh5IMVYrUCAhqq jO4HlmEaYnGy/4KnIjIIhCvgfxMgA2dC7LyZ0qW0YIjf9l6qEFu0mmGGGsY+H0IEOD 9DMc8zSWZ6QNnJtXigFQ4xCLvoc5IQVgHA8baENNnkduqgE7Lb9YoAteesynpnlgNk 9Itol08/eiPordsqMClY066Q9jwfKBmi4jL69xenD35bSFqrrjz9DSB1QdSB87jtki 4uJYi3ZnVITDfz5AizU1FJZaU46kq8G+9qNb9twQP5IbcHArwWOf4LByn1GMdSTeJq dqiKgTEAqZtOw== Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by bali.collaboradmins.com (Postfix) with ESMTPSA id 5961717E107D; Tue, 30 Sep 2025 13:34:25 +0200 (CEST) Message-ID: Date: Tue, 30 Sep 2025 13:34:24 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RESEND v4] arm64: dts: mediatek: mt7986-bpi-r3: Change fan PWM value for mid speed To: Mikhail Kshevetskiy , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Matthias Brugger , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Cc: Frank Wunderlich References: <20250930021656.1394942-1-mikhail.kshevetskiy@iopsys.eu> From: AngeloGioacchino Del Regno Content-Language: en-US In-Reply-To: <20250930021656.1394942-1-mikhail.kshevetskiy@iopsys.eu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Il 30/09/25 04:16, Mikhail Kshevetskiy ha scritto: > Popular cheap PWM fans for this machine, like the ones coming in > heatsink+fan combos will not work properly at the currently defined > medium speed. Trying different pwm setting using a command > > echo $value > /sys/devices/platform/pwm-fan/hwmon/hwmon1/pwm1 > > I found: > > pwm1 value fan rotation speed cpu temperature notes > ----------------------------------------------------------------- > 0 maximal 31.5 Celsius too noisy > 40 optimal 35.2 Celsius no noise hearable > 95 minimal > above 95 does not rotate 55.5 Celsius > ----------------------------------------------------------------- > > Thus only cpu-active-high and cpu-active-low modes are usable. > I think this is wrong. > > This patch fixes cpu-active-medium settings for bpi-r3 board. > > I know, the patch is not ideal as it can break pwm fan for some users. > Likely this is the only official mt7986-bpi-r3 heatsink+fan solution > available on the market. > > This patch may not be enough. Users may wants to tweak their thermal_zone0 > trip points, thus tuning fan rotation speed depending on cpu temperature. > That can be done on the base of the following example: > > === example ========= > # cpu temperature below 25 Celsius degrees, no rotation > echo 25000 > /sys/class/thermal/thermal_zone0/trip_point_4_temp > # cpu temperature in [25..32] Celsius degrees, normal rotation speed > echo 32000 > /sys/class/thermal/thermal_zone0/trip_point_3_temp > # cpu temperature above 50 Celsius degrees, max rotation speed > echo 50000 > /sys/class/thermal/thermal_zone0/trip_point_2_temp > ===================== > > Signed-off-by: Mikhail Kshevetskiy > Acked-by: Frank Wunderlich Reviewed-by: AngeloGioacchino Del Regno