From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AF9308F66; Thu, 5 Sep 2024 09:02:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725526926; cv=none; b=pNipCc25fKtTX25ovFsvfdoDIvohqSp5EFW1LKO3qjOVYip4THPXLuMsF678+oouluvRIwzHodJN5OQJSFhyXRuPGe4f3UPBe/4ww67f1WbwmPIM7QnLUwud7dZD6A4dCLODvzldmpUSPOCVkrLjMFaGM1kZ+z14iY3yzk28zlc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725526926; c=relaxed/simple; bh=FHKEyAvuubLDSStqDRjDFhoQhwUSFGr1cpx1VpjtTSA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BENZZTqBrcywxDz6CPsW7YiCieJX94S0PDWnQNwVhkCYE/D07Udnylme4K6xKnYH98PbWcv25X14HsRVSdUuxVHc6DTwtbjLVfIz1qh9Z7CeToZ5F10apf8/TphXryn1U2FWkaZvmHLPn2ibLdslKyMfTT+dEPjNe1weybJ3Hno= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 86DF6FEC; Thu, 5 Sep 2024 02:02:30 -0700 (PDT) Received: from [10.57.86.69] (unknown [10.57.86.69]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 688123F73F; Thu, 5 Sep 2024 02:02:02 -0700 (PDT) Message-ID: <2fe5274b-b6ea-4c70-9896-8ae6aa99e174@arm.com> Date: Thu, 5 Sep 2024 10:02:51 +0100 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 v2] thermal: sysfs: Add sanity checks for trip temperature and hysteresis To: "Rafael J. Wysocki" Cc: LKML , Zhang Rui , Linux PM , Daniel Lezcano References: <12528772.O9o76ZdvQC@rjwysocki.net> Content-Language: en-US From: Lukasz Luba In-Reply-To: <12528772.O9o76ZdvQC@rjwysocki.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/26/24 17:21, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Add sanity checks for new trip temperature and hysteresis values to > trip_point_temp_store() and trip_point_hyst_store() to prevent trip > point threshold from falling below THERMAL_TEMP_INVALID. > > However, still allow user space to pass THERMAL_TEMP_INVALID as the > new trip temperature value to invalidate the trip if necessary. > > Also allow the hysteresis to be updated when the temperature is invalid > to allow user space to avoid having to adjust hysteresis after a valid > temperature has been set, but in that case just change the value and do > nothing else. > > Fixes: be0a3600aa1e ("thermal: sysfs: Rework the handling of trip point updates") > Cc: 6.8+ # 6.8+ > Signed-off-by: Rafael J. Wysocki > --- > > v1 -> v2: > * Reorder the new check in trip_point_hyst_store() to be easier > to read (Daniel). > * Add a comment explaining the ordering of the new check in > trip_point_temp_store(). > * Allow the hysteresis to be updated when the temperature is invalid. > > This is an update of > > https://lore.kernel.org/linux-pm/7719509.EvYhyI6sBW@rjwysocki.net/ > > which is being sent separately because patch [1/2] from the original series > has been applied. > > --- > drivers/thermal/thermal_sysfs.c | 50 ++++++++++++++++++++++++++++++---------- > 1 file changed, 38 insertions(+), 12 deletions(-) > > Index: linux-pm/drivers/thermal/thermal_sysfs.c > =================================================================== > --- linux-pm.orig/drivers/thermal/thermal_sysfs.c > +++ linux-pm/drivers/thermal/thermal_sysfs.c > @@ -111,18 +111,26 @@ trip_point_temp_store(struct device *dev > > mutex_lock(&tz->lock); > > - if (temp != trip->temperature) { > - if (tz->ops.set_trip_temp) { > - ret = tz->ops.set_trip_temp(tz, trip, temp); > - if (ret) > - goto unlock; > - } > + if (temp == trip->temperature) > + goto unlock; > > - thermal_zone_set_trip_temp(tz, trip, temp); > + /* Arrange the condition to avoid integer overflows. */ > + if (temp != THERMAL_TEMP_INVALID && > + temp <= trip->hysteresis + THERMAL_TEMP_INVALID) { > + ret = -EINVAL; > + goto unlock; > + } > > - __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED); > + if (tz->ops.set_trip_temp) { > + ret = tz->ops.set_trip_temp(tz, trip, temp); > + if (ret) > + goto unlock; > } > > + thermal_zone_set_trip_temp(tz, trip, temp); > + > + __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED); > + > unlock: > mutex_unlock(&tz->lock); > > @@ -152,15 +160,33 @@ trip_point_hyst_store(struct device *dev > > mutex_lock(&tz->lock); > > - if (hyst != trip->hysteresis) { > - thermal_zone_set_trip_hyst(tz, trip, hyst); > + if (hyst == trip->hysteresis) > + goto unlock; > + > + /* > + * Allow the hysteresis to be updated when the temperature is invalid > + * to allow user space to avoid having to adjust hysteresis after a > + * valid temperature has been set, but in that case just change the > + * value and do nothing else. > + */ > + if (trip->temperature == THERMAL_TEMP_INVALID) { > + WRITE_ONCE(trip->hysteresis, hyst); > + goto unlock; > + } > > - __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED); > + if (trip->temperature - hyst <= THERMAL_TEMP_INVALID) { > + ret = -EINVAL; > + goto unlock; > } > > + thermal_zone_set_trip_hyst(tz, trip, hyst); > + > + __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED); > + > +unlock: > mutex_unlock(&tz->lock); > > - return count; > + return ret ? ret : count; > } > > static ssize_t > > > Reviewed-by: Lukasz Luba