Received-SPF: pass (google.com: domain of linux-kernel+bounces-145419-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Date: Mon, 15 Apr 2024 23:04:04 +0800
From: Huang Rui <ray.huang@amd.com>
To: "Yuan, Perry" <Perry.Yuan@amd.com>
Cc: "rafael.j.wysocki@intel.com" <rafael.j.wysocki@intel.com>,
	"Limonciello, Mario" <Mario.Limonciello@amd.com>,
	"viresh.kumar@linaro.org" <viresh.kumar@linaro.org>,
	"Shenoy, Gautham Ranjal" <gautham.shenoy@amd.com>,
	"Petkov, Borislav" <Borislav.Petkov@amd.com>,
	"Deucher, Alexander" <Alexander.Deucher@amd.com>,
	"Huang, Shimmer" <Shimmer.Huang@amd.com>,
	"oleksandr@natalenko.name" <oleksandr@natalenko.name>,
	"Du, Xiaojian" <Xiaojian.Du@amd.com>,
	"Meng, Li (Jassmine)" <Li.Meng@amd.com>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v10 7/8] cppc_acpi: print error message if CPPC is
 unsupported
Message-ID: <Zh1B5IeK53G4A2B4@amd.com>
References: <cover.1711335714.git.perry.yuan@amd.com>
 <bb32631f684446ae6380bdac0260ccd66290e222.1711335714.git.perry.yuan@amd.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <bb32631f684446ae6380bdac0260ccd66290e222.1711335714.git.perry.yuan@amd.com>
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0:
	=?us-ascii?Q?eWCW6VrHW5NBPBptGNyK2M8qKyQVry30CvyiH0RugcRdaK/zGZEcBEurRONZ?=
 =?us-ascii?Q?47wWid00MM5lkbCgFbdsPqVPxpxABUwcNQctOKZ0TArpfywn0OLKP9Ip6TDP?=
 =?us-ascii?Q?JAWbmlodPmqAktP2QUygWq+tcDICDZhDddeb/0bfw/CDTjPdISn6zstrAiFm?=
 =?us-ascii?Q?aEXdGszRsr8jZs/kUkLRi55hf9iU4OEcSnvhLXjpw+SKnusLPc6l7am1KZbR?=
 =?us-ascii?Q?iUmJ0puuTIaqbUlCJSfRVRTSNM+b1LZFUiDLJqkopfRIzf5QHzETUoVt4rLF?=
 =?us-ascii?Q?REN7jZHKAZGBaBmIuTA2vF60/S+MDesRD5rE4wgDsq3a6dqjTH2T4m1BBgxy?=
 =?us-ascii?Q?vFmjMEwWKBaW6xZwg2yr1TCA54I7LQKdhV9GKDGc65aMeqdla9arJNitriEE?=
 =?us-ascii?Q?6Jli77umHASAlx542ULACT7/Gd+q6IlfIr2gvqEogF9ZBhjCCpnK8tyB+Cyf?=
 =?us-ascii?Q?ZGCaBCjGMpna4GjJ8sc8KekTcMIeIWQo8beCaIr1W9HkaBh2TpmE6s0jFXjd?=
 =?us-ascii?Q?LhUZq8VtQFRY5PDw8kFK/uPMgdiQ7vYwVtcAtDYHiqUKHcyKR0nl1J6nv62L?=
 =?us-ascii?Q?nH+Ij/BgJM7CB32pXMsCjxs7G0RNlzDekX+u9C3gjUTjrD/5Ikw2XmDb0iMN?=
 =?us-ascii?Q?kW57fGQfTuecYSpxkMh7yrpkk5aqshFn68x7QqJe+issrVGNFHiy0/9sP4Ka?=
 =?us-ascii?Q?MkQGV8/ilSJvm+3Q8LzTnpLp6/P/iv/r2BKoLZwppQHWlf1WukFbL+fDbsMv?=
 =?us-ascii?Q?Jho68K7pRchhr9Fze9EA3S0pfhtKAXCVOUIB6OIJXr3W2otshuaOf5T4WfVu?=
 =?us-ascii?Q?uRvvkNIKeiKqmV+YSgq0OpbjMS8Fjbq5cJaJSIUxYbOgPwDvJX0LJg/czzDt?=
 =?us-ascii?Q?2RteD8l8NhCiVz9UIdvhsNJaiWf5t0zOeatpZsG2zPfqzDFbCoYvNCn9Wajn?=
 =?us-ascii?Q?YCibF8nNwTUVUKMM//bnwiO/Ppj9kyYi+OKsFuQEDO9x8k4ESaFJH00b9jHi?=
 =?us-ascii?Q?ph2mtmbA/9qNNzXMaHOsEzusKW7krg8cL4K7nvzBZvfHieHNfefR7RFMs+sk?=
 =?us-ascii?Q?wzRrjtTyhN9PGDmN0q/yZ0bs6gff127u8QEBTOgogoybeYHdQZhCeHZ+HWg9?=
 =?us-ascii?Q?CZHB60s0vHKDTIUMNPEa2J/+v8CXe2Qbay846Oeyuxtd27GFrbEKMqrPVMhP?=
 =?us-ascii?Q?RQBJFkBRSTeDOI2WqeZnieXl68ifEheu2+t61l+nwA1u0gylU0sX2kAtwyP3?=
 =?us-ascii?Q?4Q+B554U+4kVOsmHGL+WUKnlVcvkOlcPqDoa2hZjv0nu9aWSZ8eS9hettOeX?=
 =?us-ascii?Q?PoWkWnX4t5Xakej1O1jvITAxcpUbzSvansfKUUHGqFGvQXaEZ6x/IDCQ1OGq?=
 =?us-ascii?Q?KNaoOmudyyg97yE0LVOwpSNK2l+V2JCvZUzDYj8HWaa+HK4ovnC1WEzKl2Ej?=
 =?us-ascii?Q?zezsWQeQE/F244p3udYoD7SpcipwPiRaysbTIQqFhdMVHP90e1Kdblyoqz79?=
 =?us-ascii?Q?kYbM+izs2yjEskH15U47LGJiTmRTrECDIxjoAe0LS0hkYtUBMcFBj5cdHRYU?=
 =?us-ascii?Q?eBBY1HIYSZv7bEwKZARIDCXHAxkBaR+g0wHvmruN?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 654f5016-cf72-4af2-5be0-08dc5d5d58b1
X-MS-Exchange-CrossTenant-AuthSource: SJ2PR12MB8690.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Apr 2024 15:04:28.3713
 (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: PylgMxPIXwdkQUFiqW/CqVV1zMCVNMw9WWc9TrsGT9DVZkNyZwblJUIR0Y4y9XiT2uz6irz/yqBZKr9pL3qMqQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV8PR12MB9205

On Mon, Mar 25, 2024 at 11:03:27AM +0800, Yuan, Perry wrote:
> The amd-pstate driver can fail when _CPC objects are not supported by
> the CPU. However, the current error message is ambiguous (see below) and
> there is no clear way for attributing the failure of the amd-pstate
> driver to the lack of CPPC support.
> 
> [    0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled
> 
> Fix this by adding an debug message to notify the user if the amd-pstate
> driver failed to load due to CPPC not be supported by the CPU
> 
> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
> Tested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
> Signed-off-by: Perry Yuan <perry.yuan@amd.com>

Acked-by: Huang Rui <ray.huang@amd.com>

> ---
>  drivers/acpi/cppc_acpi.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 4bfbe55553f4..3134101f31b6 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -686,8 +686,10 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
>  
>  	if (!osc_sb_cppc2_support_acked) {
>  		pr_debug("CPPC v2 _OSC not acked\n");
> -		if (!cpc_supported_by_cpu())
> +		if (!cpc_supported_by_cpu()) {
> +			pr_debug("CPPC is not supported by the CPU\n");
>  			return -ENODEV;
> +		}
>  	}
>  
>  	/* Parse the ACPI _CPC table for this CPU. */
> -- 
> 2.34.1
>