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 18F7130FF13; Tue, 25 Nov 2025 11:09:00 +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=1764068943; cv=none; b=KRuy8uz49wpjYdAlsS+ecqOW7NAmW13+UJl/4v4XD3iGLYMy86RVYsIwSMSftNC2/zEgCOaL3FMFEXkXe6GeMiB0KG2r1KFL6Dj9Fl85xYR//ZAS3qCptbLq10PSjT4iv4jV9MLD6Y8hvckgmViGbUSsDpJTQzIlHlG0F+lpSp0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764068943; c=relaxed/simple; bh=Ncc5CuNSCRB/UuJ5dRZNzT+XwsBAJ0RKRhvqese24KI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Zet5AxhhpUfDx55LWETvBX35z8Bh4ceA/I4+/NjhDKRGRD+kACH9weWEwFLpjwhLc1k2D9/pS7swhwODp5Js7AdYmc2FaHNvydV0s6TPl0sbl6suTPUr8hkMwYsKiEuYWn11uy7eTiGyGALohLVtk8vsI0WVUXYhloNaGfdw1hk= 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=cBP91YTm; 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="cBP91YTm" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1764068939; bh=Ncc5CuNSCRB/UuJ5dRZNzT+XwsBAJ0RKRhvqese24KI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cBP91YTm3gUBT/0LvNQm69Cfb4fVet+PX86t57DJqyUtxyTZ4a2u+tCpDmHOXB+Tb 174vbUE/dw7ex+0Oum1XLHsL+QGlcncPNMCtxvqY75/7DOkds4dmglPP14Jkf9rvAe KX9pfxlIaUSN4xZQjIU1F3fsqcDICDbwF7wDxbKYOPpbxIxmnzSdsXilUCxVS0Ywhf U0SBTN3M5oCu1SFmbRWQdNa4DFO/xyHV7a6fnMOHRRlq6O+guJA1rm9r9FKkfw4AP8 li4Tta4VXB1ZG8DuxgI4wuXQ7t1haLBcIUUDhpUEBJnPdIecJmTFu7+9/BzYcmQC8+ hWM6+pEd9v5/Q== Received: from laura.lan (unknown [IPv6:2001:b07:646b:e2:657b:ae76:a0f8:4811]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: laura.nao) by bali.collaboradmins.com (Postfix) with ESMTPSA id BF03917E0AC3; Tue, 25 Nov 2025 12:08:57 +0100 (CET) From: Laura Nao To: daniel.lezcano@linaro.org Cc: andrew-ct.chen@mediatek.com, angelogioacchino.delregno@collabora.com, arnd@arndb.de, bchihi@baylibre.com, colin.i.king@gmail.com, conor+dt@kernel.org, devicetree@vger.kernel.org, frank-w@public-files.de, fshao@chromium.org, kernel@collabora.com, krzk+dt@kernel.org, lala.lin@mediatek.com, laura.nao@collabora.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-pm@vger.kernel.org, lukasz.luba@arm.com, matthias.bgg@gmail.com, nfraprado@collabora.com, rafael@kernel.org, robh@kernel.org, rui.zhang@intel.com, srini@kernel.org, u.kleine-koenig@baylibre.com, wenst@chromium.org Subject: Re: [PATCH v4 3/9] thermal/drivers/mediatek/lvts: Fail probe if temp_factor is zero Date: Tue, 25 Nov 2025 12:08:48 +0100 Message-Id: <20251125110848.23483-1-laura.nao@collabora.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <190003b6-2931-406a-a8f6-ec8909c65162@linaro.org> References: <190003b6-2931-406a-a8f6-ec8909c65162@linaro.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On 11/24/25 18:56, Daniel Lezcano wrote: > On 11/21/25 12:16, Laura Nao wrote: >> temp_factor is used in lvts_temp_to_raw() and lvts_raw_to_temp(). If >> platform data is incorrect and temp_factor is zero, it could cause a >> division by zero. Fail the probe early to prevent a kernel crash. >> >> Signed-off-by: Laura Nao >> --- >> drivers/thermal/mediatek/lvts_thermal.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c >> index 1c54d0b75b1a..b49441d82ffd 100644 >> --- a/drivers/thermal/mediatek/lvts_thermal.c >> +++ b/drivers/thermal/mediatek/lvts_thermal.c >> @@ -1346,6 +1346,11 @@ static int lvts_probe(struct platform_device *pdev) >> if (irq < 0) >> return irq; >> + if (!lvts_data->temp_factor) >> + return dev_err_probe( >> + dev, -EINVAL, >> + "temp_factor should never be zero; check platform data.\n"); >> + > > From my POV, this is not really useful. The temp_factor is set for each version statically in the code. The scope is limited to the driver, IOW it is not a parameter other subsystems passes to the driver. > > If it is NULL, then shame on the submitter who did not test the driver before sending ;) > Ack - I'll drop the patch in the next revision. Thanks, Laura