From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794368011; b=Ua9xYbrepFOeWkWfxKL2uu2VMmom6X9Gky33Eg9svCVObPAP4WsUUmKKMVJxVBvuGo7+ pjfFwJhpTG6In+78leB1/gk1sdLkU9UpGxGUpV7jQRDSlDlGRKxr2bsFloIGp1cXhgxmv CujeGZ3+cyg9Ey5miAfHp18v9kFeDlZzoHHofIrgwhKJ7Tid6XjLqOqSOyTbDGbDPB14q ZORcW6gsWDIDodJMoAVAB3ZFSP6gO6sAsrM7XE5Naw3QR+ZiViFpbD+nhl0cvY1xZHidr MeJVrwWcky79G9ZPk+yY29aA8o2Y1iE4Q5dg7hsdYBjYvaEmJyone9YsgbrkJ9LwHIQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794368011; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=1AuWj1mFqkp5pUXRMMdzW5vqvMcYIuWZzTOHEdwcYxQ=; b=l2ShTz1QXDrKlQXjcD8r6Jd92cO7fGamqT2US6R+SSAJ7BkZ6RXcw50O0QOJ2My0kaJ4 3doB1BjhHl9zEmIxVV6BQQDNmsfTDpccA8J7hRubb++FU3u61yUPLibh5NpHuRDPeV8jB YmJDP+zoaLh199ItrJ80keLZR8g2xqRqpto6/9SHoYdDfbElSp6YiPxWJ6jdtenY8tDZs 5mJ1Z/IGRC0fstS+WU4ocSKLgggthnsKrKUeG3oyCNBCsMQVnKVQpMO9mIMOsjcZ3wTZP /xS9yfvkhiENhkyAGrk+Nr6IdfbpxM3z+C0i2bO+mEI3BVtZEuhf6TOJNHgSGOhyJZg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ax7xi3jm; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 16122606A320 for ; Wed, 11 Nov 2026 03:33:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ax7xi3jm Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F6F31F0089F; Wed, 11 Nov 2026 03:33:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794368010; bh=1AuWj1mFqkp5pUXRMMdzW5vqvMcYIuWZzTOHEdwcYxQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ax7xi3jmCI1fqQN2wrBe+LAeAoQjBzPlKcjp2hfSxooKSpaGLOLZSzLIWJormDZs5 L78LuZwO3p/sXQPlvhl7VJnUyf6IiaRB2qN72j//ddUduRk8Wn6NtSmZ2YOJzrv338 1arRHql6WogR/nJoYfmmZsUsIIe7e7nFWaY1Cjna89XWNGPQ4FCliWmcD/nfWf3Kdw GZkLGSVGAm6mVvF6vhbUNHDK2kh2TTiweTLs0C7xTeVCcRQ/PJyVMxNVal8Z+QLqnJ 5UIqjQ1VKjzTGM7Fvr9GkM2k+N0rUo2rsyZ7jR0+RZuxpbkJu0s+pF3FUvVjJOboP4 HZta1cbwMrSQA== From: Sasha Levin To: stable@vger.kernel.org Cc: Ridham Khurana , Guenter Roeck , Sasha Levin Subject: [PATCH 5.15.y] hwmon: (lm70) Fix rounding of negative temperatures Date: Tue, 10 Nov 2026 22:33:28 -0500 Message-ID: <20261111033235.895117-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107060016-failed-5.15-eddb0aaacce4@kernel.org> References: <20261107060016-failed-5.15-eddb0aaacce4@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Ridham Khurana [ Upstream commit eddb0aaacce4baa9d8176eb2f4bd9e99e867f8fc ] temp1_input_show() drops the low bits of the temperature register by dividing the raw value (raw / 32 on the LM70). These bits are not part of the temperature: the LM70, LM71, LM74 and TMP122/TMP124 always return some of them as 1, and the TMP125 fills them with copies of the temperature LSB. Division rounds toward zero, so a negative temperature with any of these bits set is reported one LSB too high. For example, the TMP122 returns 0xffff for -0.0625 degrees C, which the driver reports as 0. The LM70 returns 0xf39f for -25 degrees C, which the driver reports as -24750. Use an arithmetic right shift instead, which drops the low bits and rounds down. Fixes: e1a8e913f97e ("[PATCH] lm70: New hardware monitoring driver") Fixes: a86e94dc946d ("hwmon: (lm70) Add support for LM71 and LM74") Fixes: cd929672a9ef ("hwmon: (lm70) Add ti,tmp125 support") Cc: stable@vger.kernel.org Signed-off-by: Ridham Khurana Link: https://patch.msgid.link/20260924205326.1739229-1-khurana.ridham222@gmail.com Signed-off-by: Guenter Roeck [ sashal: Omitted the TMP125 hunk because TMP125 support is absent. ] Signed-off-by: Sasha Levin --- drivers/hwmon/lm70.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/lm70.c b/drivers/hwmon/lm70.c index d2a60de5b8de9..0a9d7bdd0d3c1 100644 --- a/drivers/hwmon/lm70.c +++ b/drivers/hwmon/lm70.c @@ -90,17 +90,17 @@ static ssize_t temp1_input_show(struct device *dev, */ switch (p_lm70->chip) { case LM70_CHIP_LM70: - val = ((int)raw / 32) * 250; + val = ((int)raw >> 5) * 250; break; case LM70_CHIP_TMP121: case LM70_CHIP_TMP122: case LM70_CHIP_LM74: - val = ((int)raw / 8) * 625 / 10; + val = ((int)raw >> 3) * 625 / 10; break; case LM70_CHIP_LM71: - val = ((int)raw / 4) * 3125 / 100; + val = ((int)raw >> 2) * 3125 / 100; break; } -- 2.53.0