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 CB173253925; Tue, 29 Jul 2025 10:14:00 +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=1753784042; cv=none; b=iy28bpLl8cH9S/BlDFqIdSaKRHrKky4ocFZ8oHAYdy/1bF7YqqlosvCQOd0+UBRrc8eiIOcCk+XT79JbSp9R/NXeOfa82ho75d8NzGFF2suf3/JaBZil+WeXw26SPVJw3td8kddjuUT9MfhK3O/jEBObMTpAJAzbteApjPSPKN0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753784042; c=relaxed/simple; bh=KCqBt2nHHSyKsCR7eaoD8lFqx1EfG6Nptsv2HTAspbo=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=UktmQJGg/uAqsHAWQaDhvW1NZQ43XZkkloPcXR8+I9ZtjtO38xgSYoXTlBU3MXQDkvagtIi7a2yPozVz0r5ioNyEGUUNDNS8hm0hDzvSrr/xLuVolM/n3UyEM04HWSnT8pqL43V0/GxgmaIvXo3E+ONMtvWFRzpQiLx/sEvybks= 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=QsA8zBkm; 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="QsA8zBkm" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1753784039; bh=KCqBt2nHHSyKsCR7eaoD8lFqx1EfG6Nptsv2HTAspbo=; h=Date:Subject:To:References:From:In-Reply-To:From; b=QsA8zBkmIBtA+Dt3J9nOwuC2s9aRQgBIqGyC5pNtGOTwUW1KeSY5kX+nrcLGjrh4d UJ+3a/0fViXI7igUTedYX1gYRivwI/aaMx7xvs5i4xMBHMRmElf+nYyT3HCTgjMf0s TGkNv0MhLxgfbTI+4QcpOQlhuIJy29zzxBiJenyGqynRwVuctK+scZiJ5YyY+Klve9 x+sLLv3jzTH5mguySM7ik6o4icAdIF3ghBF9mrKXzcF0NAclHbpeBMOp12J323gxn+ Iik5ya1qJvOaibOh5IKqUJk/oENeFdgId900NV+rEtNNemOcAmGm7rGqisQdMdr0mk 2RPys0on3yVgw== 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 BBCA617E1284; Tue, 29 Jul 2025 12:13:58 +0200 (CEST) Message-ID: Date: Tue, 29 Jul 2025 12:13:58 +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 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, Frank Wunderlich References: <20250729075608.1651898-1-mikhail.kshevetskiy@iopsys.eu> From: AngeloGioacchino Del Regno Content-Language: en-US In-Reply-To: <20250729075608.1651898-1-mikhail.kshevetskiy@iopsys.eu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Il 29/07/25 09:56, 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