Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.32 as permitted sender) client-ip=23.128.96.32;
Message-ID: <51c2ebb4-5635-34ba-b5aa-cdfa5326dba8@huawei.com>
Date:   Thu, 28 Sep 2023 19:28:43 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.2.0
Subject: Re: [PATCH 1/3] ACPI: PCC: Add PCC shared memory region command and
 status bitfields
To:     Sudeep Holla <sudeep.holla@arm.com>
CC:     <linux-hwmon@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-i2c@vger.kernel.org>, <linux-acpi@vger.kernel.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Andi Shyti <andi.shyti@kernel.org>,
        Jean Delvare <jdelvare@suse.com>,
        Guenter Roeck <linux@roeck-us.net>
References: <20230926-pcc_defines-v1-0-0f925a1658fd@arm.com>
 <20230926-pcc_defines-v1-1-0f925a1658fd@arm.com>
 <a89bdd10-9388-01f5-6a7c-894af793e1c1@huawei.com>
 <20230927135909.6rssuywmj4k3odex@bogus>
 <fbc038e3-9719-3f90-0c09-f26318e21f38@huawei.com>
 <20230928111152.cctl3m5rwtopyg2g@bogus>
From:   "lihuisong (C)" <lihuisong@huawei.com>
In-Reply-To: <20230928111152.cctl3m5rwtopyg2g@bogus>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk


在 2023/9/28 19:11, Sudeep Holla 写道:
> On Thu, Sep 28, 2023 at 11:49:25AM +0800, lihuisong (C) wrote:
>> 在 2023/9/27 21:59, Sudeep Holla 写道:
>>> On Wed, Sep 27, 2023 at 10:07:15AM +0800, lihuisong (C) wrote:
> [...]
>
>>>>> +/* Generic Communications Channel Shared Memory Region */
>>>>> +#define PCC_SIGNATURE			0x50424300
>>>> Why is this signature 0x50424300?
>>> It is as per the specification.
>>>
>>>> In ACPI spec, this signature is all 0x50434303.
>>> No, not exactly. It is just an example.
>>> The PCC signature - The signature of a subspace is computed by a bitwise-or
>>> of the value 0x50434300 with the subspace ID. For example, subspace 3 has
>>> signature 0x50434303
>> Sorry for my mistake. I know this.
>> I mean, why doesn't the following macro follow spec and define this
>> signature as 0x504*3*430.
>> "#define PCC_SIGNATURE **0x504*2*4300*"*
>> Because it seems that all version of ACPI spec is 0x5043430.
> Sorry my mistake. Stupidly the existing drivers have it wrong and I just
> copied them without paying much attention. I will fix it up. It must be
> 0x50434300 instead of 0x50424300. If you have no other comments, can you
They are very similar.????
> please ack v2 patch 4/4 changing soc kunpeng_hccs driver. I will fixup
> the PCC_SIGNATURE and send it as part of my PR to Rafael.
ok
>
> Refer [1] for the change in PCC_SIGNATURE, sorry for missing the point. I
> was confident that the existing code is correct :), but I am wrong.
>