Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) client-ip=2620:137:e000::3:1;
Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates
 216.228.117.160 as permitted sender) receiver=protection.outlook.com;
 client-ip=216.228.117.160; helo=mail.nvidia.com; pr=C
Message-ID: <4be60668-09dc-d86a-ec22-d5e06381deb8@nvidia.com>
Date:   Fri, 20 Oct 2023 00:00:53 +0530
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Subject: Re: [Patch v5 1/2] ACPI: thermal: Add Thermal fast Sampling Period
 (_TFP) support
Content-Language: en-US
To:     "Rafael J. Wysocki" <rafael@kernel.org>
CC:     <rui.zhang@intel.com>, <lenb@kernel.org>,
        <linux-acpi@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <treding@nvidia.com>,
        <jonathanh@nvidia.com>, <bbasu@nvidia.com>, <sanjayc@nvidia.com>,
        <ksitaraman@nvidia.com>, <srikars@nvidia.com>,
        <jbrasen@nvidia.com>, Sumit Gupta <sumitg@nvidia.com>
References: <20231014105426.26389-1-sumitg@nvidia.com>
 <20231014105426.26389-2-sumitg@nvidia.com>
 <CAJZ5v0jm5h9qeZdnLDp9qUMT-31FOWMBERMzhFzgFsmt9QX78g@mail.gmail.com>
From:   Sumit Gupta <sumitg@nvidia.com>
In-Reply-To: <CAJZ5v0jm5h9qeZdnLDp9qUMT-31FOWMBERMzhFzgFsmt9QX78g@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 8bit
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Oct 2023 18:31:13.3083
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: a3c9bb04-1f6b-4683-1b4d-08dbd0d192f4
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.160];Helo=[mail.nvidia.com]
X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000E9CE.namprd03.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR12MB9316
X-Spam-Status: No, score=-4.2 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS
	autolearn=unavailable autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on morse.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (morse.vger.email [0.0.0.0]); Thu, 19 Oct 2023 11:31:25 -0700 (PDT)


On 18/10/23 17:18, Rafael J. Wysocki wrote:
> External email: Use caution opening links or attachments
> 
> 
> On Sat, Oct 14, 2023 at 12:54 PM Sumit Gupta <sumitg@nvidia.com> wrote:
>>
>> From: Jeff Brasen <jbrasen@nvidia.com>
>>
>> Add support of "Thermal fast Sampling Period (_TFP)" for Passive cooling.
>> As per [1], _TFP overrides the "Thermal Sampling Period (_TSP)" if both
>> are present in a Thermal zone.
>>
>> [1] ACPI Specification 6.4 - section 11.4.17. _TFP (Thermal fast Sampling
>>      Period)"
>>
>> Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
>> Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
>> ---
>>   drivers/acpi/thermal.c | 17 +++++++++++------
>>   1 file changed, 11 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
>> index d98ff69303b3..a91e3d566858 100644
>> --- a/drivers/acpi/thermal.c
>> +++ b/drivers/acpi/thermal.c
>> @@ -90,7 +90,7 @@ struct acpi_thermal_passive {
>>          struct acpi_thermal_trip trip;
>>          unsigned long tc1;
>>          unsigned long tc2;
>> -       unsigned long tsp;
>> +       unsigned long passive_delay;
> 
> This is a passive trip structure anyway, so the "passive_" prefix is
> redundant here.  "delay" alone would be fine.
> 
will change in v6.

>>   };
>>
>>   struct acpi_thermal_active {
>> @@ -404,11 +404,16 @@ static bool passive_trip_params_init(struct acpi_thermal *tz)
>>
>>          tz->trips.passive.tc2 = tmp;
>>
>> -       status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
>> -       if (ACPI_FAILURE(status))
>> -               return false;
>> +       status = acpi_evaluate_integer(tz->device->handle, "_TFP", NULL, &tmp);
>> +       if (ACPI_FAILURE(status)) {
>> +               status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
>> +               if (ACPI_FAILURE(status))
>> +                       return false;
>>
>> -       tz->trips.passive.tsp = tmp;
>> +               tz->trips.passive.passive_delay = tmp * 100;
>> +       } else {
>> +               tz->trips.passive.passive_delay = tmp;
>> +       }
> 
> I would prefer the if () statement above to be structured the other
> way around, that is
> 
>   status = ...
>   if (ACPI_SUCCESS(status)) {
>          tz->trips.passive.delay = tmp;
>          return true;
> }
> 
> status = ...
> if (ACPI_FAILURE(status))
>           return false;
> 
> etc.
> 

Ok. will change in v6.

>>
>>          return true;
>>   }
>> @@ -904,7 +909,7 @@ static int acpi_thermal_add(struct acpi_device *device)
>>
>>          acpi_trip = &tz->trips.passive.trip;
>>          if (acpi_thermal_trip_valid(acpi_trip)) {
>> -               passive_delay = tz->trips.passive.tsp * 100;
>> +               passive_delay = tz->trips.passive.passive_delay;
>>
>>                  trip->type = THERMAL_TRIP_PASSIVE;
>>                  trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
>> --
>> 2.17.1
>>