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Subject: Re: [PATCHv1 3/4] dt-bindings: fpga: add authenticate-fpga-config
 property
To:     Xu Yilun <yilun.xu@intel.com>, Moritz Fischer <mdf@kernel.org>
Cc:     trix@redhat.com, linux-fpga@vger.kernel.org,
        linux-kernel@vger.kernel.org, dinguyen@kernel.org,
        sridhar.rajagopal@intel.com, Richard Gong <richard.gong@intel.com>
References: <1605204403-6663-1-git-send-email-richard.gong@linux.intel.com>
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 <20201116024758.GA6810@yilunxu-OptiPlex-7050>
From:   Richard Gong <richard.gong@linux.intel.com>
Message-ID: <d83b37c2-2baa-b366-8ca4-bb2924bcd4f9@linux.intel.com>
Date:   Mon, 16 Nov 2020 08:14:52 -0600
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Hi Yilun,

On 11/15/20 8:47 PM, Xu Yilun wrote:
> On Sun, Nov 15, 2020 at 11:21:06AM -0800, Moritz Fischer wrote:
>> Hi Richard,
>>
>> On Thu, Nov 12, 2020 at 12:06:42PM -0600, richard.gong@linux.intel.com wrote:
>>> From: Richard Gong <richard.gong@intel.com>
>>>
>>> Add authenticate-fpga-config property for FPGA bitstream authentication.
>>>
>>> Signed-off-by: Richard Gong <richard.gong@intel.com>
>>> ---
>>>   Documentation/devicetree/bindings/fpga/fpga-region.txt | 1 +
>>>   1 file changed, 1 insertion(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/fpga/fpga-region.txt b/Documentation/devicetree/bindings/fpga/fpga-region.txt
>>> index e811cf8..7a512bc 100644
>>> --- a/Documentation/devicetree/bindings/fpga/fpga-region.txt
>>> +++ b/Documentation/devicetree/bindings/fpga/fpga-region.txt
>>> @@ -187,6 +187,7 @@ Optional properties:
>>>   - external-fpga-config : boolean, set if the FPGA has already been configured
>>>   	prior to OS boot up.
>>>   - encrypted-fpga-config : boolean, set if the bitstream is encrypted
>>> +- authenticate-fpga-config : boolean, set if do bitstream authentication
>> It is unclear to me from the description whether this entails
>> authentication + reconfiguration or just authentication.
>>
>> If the latter is the case this should probably be described as such.
> 
> If it is just authentication, do we still need to disable bridges in
> fpga_region_program_fpga?
> 

Yes.

Except for the actual configuration of the device, the authentication 
feature is the same as FPGA configuration.

Regards,
Richard

> I'm wondering if the FPGA functionalities could still be working when
> the authenticating is ongoing, or when the authenticating is failed.
> 


> Thanks,
> Yilun
> 
>>
>>>   - region-unfreeze-timeout-us : The maximum time in microseconds to wait for
>>>   	bridges to successfully become enabled after the region has been
>>>   	programmed.
>>> -- 
>>> 2.7.4
>>>
>>
>> Thanks