Re: [PATCH v3 06/21] cpufreq: amd: introduce a new amd pstate driver to support future processors

From: Nathan Fontenot
Date: Thu Nov 04 2021 - 11:11:14 EST


On 11/3/21 2:01 AM, Huang Rui wrote:

>>> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
>>> new file mode 100644
>>> index 000000000000..a400861c7fdc
>>> --- /dev/null
>>> +++ b/drivers/cpufreq/amd-pstate.c
>>> @@ -0,0 +1,413 @@
>>> +/*
>>> + * amd-pstate.c - AMD Processor P-state Frequency Driver
>>> + *
>>> + * Copyright (C) 2021 Advanced Micro Devices, Inc. All Rights Reserved.
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public License
>>> + * as published by the Free Software Foundation; either version 2
>>> + * of the License, or (at your option) any later version.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License along with
>>> + * this program; if not, write to the Free Software
>>> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
>>
>> You should use a SPDX license identifier instead of copying the GPL text
>> in the file. See Documentation/process/license-rules.rst
>
> The SPDX license identifier is an alternative way to instead of the common
> way to express the license at the top comment of the file. Acutally it's
> not mandatory, right?
>

It's not mandatory but I believe using SPDX identifiers is the preferred method.

...

>>> +static int __init amd_pstate_init(void)
>>> +{
>>> + int ret;
>>> +
>>> + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
>>> + return -ENODEV;
>>> +
>>> + if (!acpi_cpc_valid()) {
>>> + pr_debug("%s, the _CPC object is not present in SBIOS\n",
>>> + __func__);
>>
>> Do we need to print the function name here (and below)?
>
> It's a soft reminder to tell the user where the message comes from.
>

True, but you do define pr_fmt at the top of the file so users will know
this is coming from the amd_pstate driver.

-Nathan