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Shenoy" , Perry Yuan Cc: "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "open list:CPU FREQUENCY SCALING FRAMEWORK" , Mario Limonciello References: <20250321022858.1538173-1-superm1@kernel.org> <20250321022858.1538173-6-superm1@kernel.org> Content-Language: en-US From: Dhananjay Ugwekar In-Reply-To: <20250321022858.1538173-6-superm1@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SG2PR02CA0136.apcprd02.prod.outlook.com (2603:1096:4:188::16) To LV8PR12MB9207.namprd12.prod.outlook.com (2603:10b6:408:187::15) Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9207:EE_|PH7PR12MB6396:EE_ X-MS-Office365-Filtering-Correlation-Id: 61a86059-8d3b-413f-6001-08dd6ac69bf6 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?UHdWSEw0bHBmWVg3cHczb3BodEIzMkRiYUxCZjBpc29od2d0NlFmZmdjcjAr?= =?utf-8?B?RmNncnNjUGhRRmovTmFzd1Q3RE8xMGNDYVhQcFAvVzFmVFE3cEFoVGhGY2lj?= =?utf-8?B?WnlLWFc2alQ1SU5JWVVjOHp1bGQvSnZBKzd2R1J4S1VxVnFNVjhPNUozUGVD?= =?utf-8?B?TjQ1akpuU2tGVkRRVlFlZmtoYmh3MXY4cUlaYUpUK3hQeGFNc01wWE5MY2Fu?= =?utf-8?B?cVRZV2FMMVh4ZVozb3h3STNEdVh1QkQ2ZkJybTFnRk1sdzBKSjBPSWtoR3dO?= =?utf-8?B?STFabDNOb2ZpSEJVRzhWOTdnc2RHOGxUTENSNnU3Y2VWVXpSdHYraG1EdUNE?= =?utf-8?B?b1pKc0RYYjBFKy9LdDMwdlhTNy9EWm9pTnpaUzFZbzVEM1JyVDc4UU5LR1RU?= =?utf-8?B?UnlUa0szVi9lK0pLOFVJNkJEQkFwYVNBNzVpQTBWM2g0TTZwcmlGTytzRC9v?= =?utf-8?B?Z3pMb3pGUzdHLzQ3MXM4VG9vaDFDTm4wT2VtMktZNzNYOEVkcjFSMWkrK3Bm?= =?utf-8?B?MmhvUlNNV0hzMW8rT1hKSENpVk5nTE5aTmd4RCs4SUUxZHpPSnVmZjUxNG10?= =?utf-8?B?R3V1aDM2MkZHeVpGQzBldmtmRzUzWjdBZVhYa2VrbnJiVDF0Zk1sOXBRM3p2?= =?utf-8?B?SzJzUjFOY0JHVFZQNFB0dks4QUdhb21sak4ydllCQ0s4QTdxUkcyUlh2b3Iw?= =?utf-8?B?a1o4TXZTTkUrVklBQlZ6aXcyb1lGMXZUTlA1N08vU3dTSk16NUFySTk5SVEv?= =?utf-8?B?VENIRzVRRHNiK2l4cUgrM0p3eVNwUzlTbldiSTdjcjl1UUpNekUyYmFmWHRF?= =?utf-8?B?bEtBOVUva0NUOTdNTmhiR0dVVFppOHNEVkpDMGNMUDI3RCt5NWlOZmdiQWZu?= =?utf-8?B?aXJMdVU3TDhYZkR3TEZDZXRCTzZVRFFtZC9UTGVtWFBvNm1QSDc4S0JlbUJv?= =?utf-8?B?NGNhelZoUlNsbTNMbldZYTVrRnkzajNjemQ2d0dKcFZUR1FhdWR0cXQ3ams4?= =?utf-8?B?R2M0aXpFdFFhZXRpRzZGc1NCS01wUmRkSDZzaUZDeGE2ZWI1MlVCWFFNcUFD?= =?utf-8?B?TVJJQTFpcmExdGsxTzB3SjJGK2VMYkdQMVJYb0JmeG9sZDdyOHJ0U3VUNXRW?= =?utf-8?B?QkdGREs3RVUvaFRhd1dkS3JsWDVYd1BqMVMwRTFzSXpYQ2F5b3NZa3Q3WEdM?= =?utf-8?B?b0dCOWRadzQ2dmxtWTBZTHJIaC9ZVVh0VmZDY0dhR2Y1NnN1bUdEWjVBU3dj?= =?utf-8?B?Mmh3WFhNeUk4ZVdLUGdCdWI2VlVxdU5XVFl6RjlvWHJHdnZYektrMHpVRm80?= =?utf-8?B?U0E4eGNCUWpaZ3UzV0xxcG04MG1ldHZ0eU9VeHZDYUkvUEZCc1pEa09pN0xq?= =?utf-8?B?Vm5HZWR1T3ErSzdTK0lkdHVZWFg3QUJwaEJmVmVTTU44U1FLUFJYbFRrZnQz?= =?utf-8?B?TjFGalNya1F4cHpxRjUyV1BsMmhxa3BlYTNna3IvTnVjOVNIUG8zOUdPa1BH?= =?utf-8?B?WldzbURteWR2aUdjbVRZYndCdkFSeUIzOXcrZEFQelFscTdjRDNLaWZlMDhG?= =?utf-8?B?aXR1OStId0xtUnZKUkdMUkhVbHFCeGxwNFpUOG91OHQyK3g3RHYzRGJWbzk3?= =?utf-8?B?d3hsQVNEWHVDeDNWVGIxb1J1aDRTdTJYekRhRFNFNDlzYWhyUmJaVU5aWTd3?= =?utf-8?B?SHZoYnR4b2pvdHcyZ1JKV1dEMUpudWVORmtvWVluUGhTQTVOa1pFN0FCbGVC?= =?utf-8?B?RnkyMFFzNFJsY2hzTEsxK01PY0U3SXg2QUhnOTdUTG1OeDl4R3haVlBNMXF1?= =?utf-8?B?Yk9HNU1GZ21VL3lOaEJwQ0JTb01DK09Ycm0zbkc4K1NrUkRBYWlEZHFDRmEv?= =?utf-8?Q?JKCdIiGxKEhhG?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:LV8PR12MB9207.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(366016)(376014);DIR:OUT;SFP:1101; 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> @@ -46,6 +48,7 @@ static int amd_pstate_ut_acpi_cpc_valid(u32 index); > static int amd_pstate_ut_check_enabled(u32 index); > static int amd_pstate_ut_check_perf(u32 index); > static int amd_pstate_ut_check_freq(u32 index); > +static int amd_pstate_ut_epp(u32 index); > static int amd_pstate_ut_check_driver(u32 index); > > static struct amd_pstate_ut_struct amd_pstate_ut_cases[] = { > @@ -53,6 +56,7 @@ static struct amd_pstate_ut_struct amd_pstate_ut_cases[] = { > {"amd_pstate_ut_check_enabled", amd_pstate_ut_check_enabled }, > {"amd_pstate_ut_check_perf", amd_pstate_ut_check_perf }, > {"amd_pstate_ut_check_freq", amd_pstate_ut_check_freq }, > + {"amd_pstate_ut_epp", amd_pstate_ut_epp }, > {"amd_pstate_ut_check_driver", amd_pstate_ut_check_driver } > }; > > @@ -239,6 +243,60 @@ static int amd_pstate_set_mode(enum amd_pstate_mode mode) > return amd_pstate_update_status(mode_str, strlen(mode_str)); > } > > +static int amd_pstate_ut_epp(u32 index) > +{ > + struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL; > + void *buf __free(free_page) = NULL; > + struct amd_cpudata *cpudata; > + int ret, cpu = 0; > + u16 epp; > + > + policy = cpufreq_cpu_get(cpu); > + if (!policy) > + return -ENODEV; > + > + cpudata = policy->driver_data; > + > + /* disable dynamic EPP before running test */ > + if (cpudata->dynamic_epp) { > + pr_debug("Dynamic EPP is enabled, disabling it\n"); > + amd_pstate_clear_dynamic_epp(policy); > + } > + > + buf = (void *)__get_free_page(GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + > + ret = amd_pstate_set_mode(AMD_PSTATE_ACTIVE); This causes a deadlock, as we are holding cpufreq_policy reference and calling set_mode(), which needs to unregister the cpufreq subsystem (i.e. needs all cpufreq_policy references freed). We might need to drop and retake the reference around set_mode(). Also make cpudata variable NULL to avoid anyone using a stale cpudata pointer later on by mistake. OR Directly call set_epp() instead of store_energy_performance_preference() and eliminate the need of policy ref after set_mode(). > + if (ret) > + return ret; > + > + for (epp = 0; epp <= U8_MAX; epp++) { > + u8 val; > + > + /* write all EPP values */ > + memset(buf, 0, sizeof(*buf)); > + snprintf(buf, PAGE_SIZE, "%d", epp); > + ret = store_energy_performance_preference(policy, buf, sizeof(*buf)); > + if (ret < 0) > + return ret; > + > + /* check if the EPP value reads back correctly for raw numbers */ > + memset(buf, 0, sizeof(*buf)); > + ret = show_energy_performance_preference(policy, buf); > + if (ret < 0) > + return ret; > + strreplace(buf, '\n', '\0'); > + ret = kstrtou8(buf, 0, &val); > + if (!ret && epp != val) { > + pr_err("Raw EPP value mismatch: %d != %d\n", epp, val); > + return -EINVAL; > + } > + } > + > + return 0; > +} > + > static int amd_pstate_ut_check_driver(u32 index) > { > enum amd_pstate_mode mode1, mode2 = AMD_PSTATE_DISABLE;