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Subject: Re: [PATCH] ACPI: nfit: adjust annotation for why return 0 if fail to
 find NFIT at startup
To:     "Verma, Vishal L" <vishal.l.verma@intel.com>,
        "Williams, Dan J" <dan.j.williams@intel.com>,
        "ross.zwisler@linux.intel.com" <ross.zwisler@linux.intel.com>,
        "oceanhehy@gmail.com" <oceanhehy@gmail.com>,
        "lenb@kernel.org" <lenb@kernel.org>,
        "rjw@rjwysocki.net" <rjw@rjwysocki.net>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
        "linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
        "hehy1@lenovo.com" <hehy1@lenovo.com>
References: <1533622531-3617-1-git-send-email-oceanhehy@gmail.com>
 <1533669914.18175.28.camel@intel.com>
From:   Dave Jiang <dave.jiang@intel.com>
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Message-ID: <45efa554-72af-9266-e841-e42e8741fed9@intel.com>
Date:   Tue, 7 Aug 2018 15:46:42 -0700
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On 08/07/2018 12:25 PM, Verma, Vishal L wrote:
> 
> On Tue, 2018-08-07 at 02:15 -0400, Ocean He wrote:
>> From: Ocean He <hehy1@lenovo.com>
> 
> Just some minor nits in commit message wording:
> 
>>
>> Add detail explanation why it's ok to return 0 if fail to find NFIT at
>       detailed          ^for                       ^we          ^an
>> startup, refer to chapter 9.20.2 NVDIMM Root Device in ACPI 6.2 spec.
>          . Refer
> 
> Perhaps Dave can fixup while applying..

Applied and updated.

>>
>> Signed-off-by: Ocean He <hehy1@lenovo.com>
>> ---
>> v1: https://lists.01.org/pipermail/linux-nvdimm/2018-August/017311.html 
>> v2: Per Vishal's comments of v1, it turns out that it's right to keep 
>> "return 0" if NFIT not found at boot time. This v2 adjust annotation
>> to avoid misunderstanding of "return 0".
> 
> Looks good, thanks for the update. Feel free to add:
> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
> 
>>
>>  drivers/acpi/nfit/core.c | 8 +++++++-
>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
>> index 7c47900..1b982fe 100644
>> --- a/drivers/acpi/nfit/core.c
>> +++ b/drivers/acpi/nfit/core.c
>> @@ -3353,7 +3353,13 @@ static int acpi_nfit_add(struct acpi_device *adev)
>>  
>>  	status = acpi_get_table(ACPI_SIG_NFIT, 0, &tbl);
>>  	if (ACPI_FAILURE(status)) {
>> -		/* This is ok, we could have an nvdimm hotplugged later */
>> +		/* The NVDIMM root device allows OS to trigger enumeration of
>> +		 * NVDIMMs through NFIT at boot time and re-enumeration at
>> +		 * root level via the _FIT method during runtime.
>> +		 * This is ok to return 0 here, we could have an nvdimm
>> +		 * hotplugged later and evaluate _FIT method which returns
>> +		 * data in the format of a series of NFIT Structures.
>> +		 */
>>  		dev_dbg(dev, "failed to find NFIT at startup\n");
>>  		return 0;
>>  	}