Received-SPF: pass (google.com: domain of linux-kernel+bounces-83513-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Message-ID: <f1964180-458f-4c22-90f6-bda2aee5dbf8@amd.com>
Date: Tue, 27 Feb 2024 09:36:34 -0600
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH] cpufreq: amd-pstate: adjust min/max limit perf
Content-Language: en-US
To: Meng Li <li.meng@amd.com>, "Rafael J . Wysocki"
 <rafael.j.wysocki@intel.com>, Huang Rui <ray.huang@amd.com>
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org,
 linux-acpi@vger.kernel.org, Shuah Khan <skhan@linuxfoundation.org>,
 linux-kselftest@vger.kernel.org, Nathan Fontenot <nathan.fontenot@amd.com>,
 Deepak Sharma <deepak.sharma@amd.com>,
 Alex Deucher <alexander.deucher@amd.com>,
 Shimmer Huang <shimmer.huang@amd.com>, Perry Yuan <Perry.Yuan@amd.com>,
 Xiaojian Du <Xiaojian.Du@amd.com>, Viresh Kumar <viresh.kumar@linaro.org>,
 Borislav Petkov <bp@alien8.de>
References: <20240227073924.3573398-1-li.meng@amd.com>
From: Mario Limonciello <mario.limonciello@amd.com>
In-Reply-To: <20240227073924.3573398-1-li.meng@amd.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0:
	=?utf-8?B?OFpoK1dIQTlNZnVnRVhielFobkpDMjlLZ0VZM2JTY3BiNGZxUnU2RXB3SUd5?=
 =?utf-8?B?dUtUa3VBd2lENExGdDF5Tk5KNXRHQWE1V1VBVkdaUTRnTkxRbFJVaGIvS0lX?=
 =?utf-8?B?Rm50SWlzdlFOTkRyTlVYZmtURngxU2NDOEl5aHM5UkhVQmd3b3lKV1h6ZFBy?=
 =?utf-8?B?OGRacEVGY3pmcm1iQ3hISElxTVlyWEdpZEF5MlYxS1J6OTNlNUpReEdpdk5x?=
 =?utf-8?B?ckpTRWwvRSs1M2M0M2pwbS9CdjFON0MySWh6NTR0U1lPcERTOEJ4b2twcnNB?=
 =?utf-8?B?QW0wVnQ4WXNBa0Rtb2JFell6UCt4eVBiOUZzNU1uaytvWEkwR29HTmNjUENm?=
 =?utf-8?B?eFBXaWhmNUhzZkJNR2VHbWJYNFpCeVJobnR1YldMdDNDNTAzeHo0enlRREZ2?=
 =?utf-8?B?TFlrZ0E1WEx1TlZmaTNOR1lya1BoQXA5cThzV3hLcGZ5TUtnVlp4dHBMUXp4?=
 =?utf-8?B?U1ZIdHg2YkFLOU55SXU5WGFxbnR6MWVQV3Z0T3luNGdqV2NXYnB4RFprZzh5?=
 =?utf-8?B?NllNNnJkNlp6aTBscEhTaG5tdUhDeHNubGNHb3A1bU1ZR1FFT0NmU0xSdDVV?=
 =?utf-8?B?OU55L3RSblhMMUF4LzI3UUpvYlpwZllCLy92OTFoVHJ6TVliOXo5eUpZNHli?=
 =?utf-8?B?Z0JIRHRkN2drTy8rb0I1V1hsS01lUFdieWpMbEw1V2VIenhXN3NvOU9UendE?=
 =?utf-8?B?U1hJZFRhdnZQbjhOOENLWXhKY2VSZ2kydDMweE8yZzhRNDNRK0ZiYXpUUUY5?=
 =?utf-8?B?QzRBRTdkMGhRQnd0eGh1aGQxUGc0WVAwNUsxVmJSS2lGSmVOdmltaDVXeE96?=
 =?utf-8?B?VkpxR0NrUG04YkF2blpVR3UreElkcENwemkyTVNUT0VoWk55RmJjaG9JM0Ft?=
 =?utf-8?B?NVVaais5RHQ1cnhmUVpUMnlYUVJDQ09OZ010cWl2SFVRbUZIL3l6ekVLSmJm?=
 =?utf-8?B?WE5SSURwRTRyeFJQU3VOMDVzbFg3cVZGcnRHS213TjlVTlhNNCsrbjNIL1Rv?=
 =?utf-8?B?a0pPVG8zalRrZko4cy9JeVZwWC9ab2oyQk1Sb1hvaXFxajI1dlZlbWRkVjhN?=
 =?utf-8?B?eTVLbk9yZ2ZPUlNINFZjdUxncUlJMUxicHJIblpER3RaMGNQRkxKVlVua0ZK?=
 =?utf-8?B?MVp5a0h4L0xiQUtZVy9KYm91cThrU0N4TFROQ3NQYUVPaVlVeUgydEtyVDZT?=
 =?utf-8?B?cEhEWGh6b2VBUXJsdFU0bEpuZXM1SVptMVp6Q0pjb0tUSW0xeFhmZ2JKZWJO?=
 =?utf-8?B?SW95SUdCTmdDbENFcHdaUXVQZnVhYk0yaUlQTm1pNisrdnQ5R29uTlhUczVr?=
 =?utf-8?B?K3prMjhHbGhaaWdCV0xnbWpnTWZRZHhleEpZRTR3dTUvdGJqZVF2MXdKVlA3?=
 =?utf-8?B?VG90dlAwOVVadTNqa1ZLM2MrVWpzTnNua0dYY3cxVmVhWE5NaHZUaGhhY1JV?=
 =?utf-8?B?ZmRkMU12ZTNZWFM2azRyVmN1R01mUVoxODJEb3dhK1VTZnMzRThOdWFUMTdG?=
 =?utf-8?B?T3RpeWMyY3FwNTFDTUtVUnR5cjluaUlTVXhTSW1sZDFLV0JnOVVwWVZobG1o?=
 =?utf-8?B?T1N4ZFVVUmhQVkN4ZHlwRlRmSVh1UHA2UnNETU9oWmoxV2ZyWWtZYTM2RlZr?=
 =?utf-8?B?dFdhb3BqZUxMVmo4T3dFbUQvL1hISHFiaFdqUlVWd0xVWWJQVG9uYUZ3WFpR?=
 =?utf-8?B?aVF3bGsyb1pnRGRWbjRxNFhOVWV4QXpzckZ2clpHVlh2N09UM3JvZTBMdVM5?=
 =?utf-8?B?bWpjMU9wMXkvNUMvbm81ODZlenhRZ0dWVmdXSk1ldGFDZ094QXZvY3JTZkQv?=
 =?utf-8?B?NnpPTXVRWWs3UHFNbTNrYVdYVEtNemM2ZXpsZitkdWw1V0JmbHVLYUZ6eG9s?=
 =?utf-8?B?RVp5eW1Sbms3OG9SbWlwWWxyREVHdyt1V1VJMm9saFg5MjBLeDNkbFg4dGR6?=
 =?utf-8?B?VUdNRGJPTXJwN0JIaDd5RFJPOE83cVcrQWhWc2pqZXpXTTMrMzhmbFIxQlRv?=
 =?utf-8?B?TnQ0MVRHUG4raWpDUThGOHdMVGw0S3l5Wktva0ZROHV1V1NXcVQ1cXBHcnpw?=
 =?utf-8?B?UllyM1hMTlpaQndYVGdLTE9mdjQyUTh1amdtRjYxazZhUjdmREtqUkpGSUlF?=
 =?utf-8?Q?sSZWVMdz0aPdrJjK6laLTcECa?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 838d68bf-5516-41da-42b2-08dc37a9e2de
X-MS-Exchange-CrossTenant-AuthSource: MN0PR12MB6101.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Feb 2024 15:36:37.6400
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 77FanXQQMeB3187hML3K0CYGRChwQ95UjBEoounWYIiyEjZ2nrnvVveMd11lyO6t5Ie6Ebb/UibY76zVfpkNgg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB8289

On 2/27/2024 01:39, Meng Li wrote:
> The min/max limit perf values calculated based on frequency
> may exceed the reasonable range of perf(highest perf, lowest perf).
> 
> Signed-off-by: Meng Li <li.meng@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>   drivers/cpufreq/amd-pstate.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index aa5e57e27d2b..2015c9fcc3c9 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -484,12 +484,19 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy)
>   
>   static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
>   {
> -	u32 max_limit_perf, min_limit_perf;
> +	u32 max_limit_perf, min_limit_perf, lowest_perf;
>   	struct amd_cpudata *cpudata = policy->driver_data;
>   
>   	max_limit_perf = div_u64(policy->max * cpudata->highest_perf, cpudata->max_freq);
>   	min_limit_perf = div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq);
>   
> +	lowest_perf = READ_ONCE(cpudata->lowest_perf);
> +	if (min_limit_perf < lowest_perf)
> +		min_limit_perf = lowest_perf;
> +
> +	if (max_limit_perf < min_limit_perf)
> +		max_limit_perf = min_limit_perf;
> +
>   	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
>   	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
>   	WRITE_ONCE(cpudata->max_limit_freq, policy->max);
> @@ -1387,6 +1394,12 @@ static void amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
>   	max_limit_perf = div_u64(policy->max * cpudata->highest_perf, cpudata->max_freq);
>   	min_limit_perf = div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq);
>   
> +	if (min_limit_perf < min_perf)
> +		min_limit_perf = min_perf;
> +
> +	if (max_limit_perf < min_limit_perf)
> +		max_limit_perf = min_limit_perf;
> +
>   	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
>   	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
>