Message-ID: <2713f092-5d21-ad5e-c5f4-87c927b18a27@enneenne.com>
Date:   Fri, 17 Mar 2023 15:04:31 +0100
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Subject: Re: [PATCH v4] pps: Add elapsed realtime timestamping
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To:     Alex Komrakov <alexander.komrakov@broadcom.com>,
        Greg KH <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org
References: <20230317074739.193965-1-alexander.komrakov@broadcom.com>
 <ZBQdWRHzakFLzSkb@kroah.com>
 <CAMedr-_ssg-baCz94ExMVTeXr2Qivzop1kEpx0S4PWuQdAiGaw@mail.gmail.com>
From:   Rodolfo Giometti <giometti@enneenne.com>
In-Reply-To: <CAMedr-_ssg-baCz94ExMVTeXr2Qivzop1kEpx0S4PWuQdAiGaw@mail.gmail.com>
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On 17/03/23 10:51, Alex Komrakov wrote:
>> +     if (!(pps->info.mode & PPS_CAPTURECLEAR))
>> +             return 0;   Why are you not returning an error?
> [AK] I used the style in this file sysfs.c.
>   assert_show() and clear_show()  have the same condition.
> When '& PPS_CAPTURECLEAR' -- 0 means no interrupt asserted  and it is not error
> Probably Rodolfo can get more info why return 0

It's just as Alex said, if the PPS source has no PPS_CAPTUREASSERT or 
PPS_CAPTURECLEAR mode it should not print ASSERT and CLEAR info.

> And why are these sysfs files even present if the mode is not set
> properly?  Can the mode be set while the device is attached or is this
> only defined at probe time?  If at probe time, just never create these
> files.
> [AK] we can understand mode is set when interrupts asserted and  
> file assert_elapsed will be updated.

PPS source's "mode bits" can be set at runtime via PPS_SETPARAMS.

Ciao,

Rodolfo

-- 
GNU/Linux Solutions                  e-mail: giometti@enneenne.com
Linux Device Driver                          giometti@linux.it
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