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Subject: Re: question about IIO buffer interface
To: Jonathan Cameron <jic23@kernel.org>
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 <1033a3e3-51e3-a962-15d5-a7002795033b@kernel.org>
CC: "linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
        Lorenzo BIANCONI <lorenzo.bianconi@st.com>,
        Denis CIOCCA <denis.ciocca@st.com>
From: Armando Visconti <armando.visconti@st.com>
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Date: Fri, 16 Sep 2016 17:03:10 +0200
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Hello Jonathan,

Thx for the very long explanation.


>
> Anyhow, the philosophy was:
>
> preenable -> stuff related to getting ready for buffered operation.
> This might be as simple as turning off something else that prevents
> buffered operation. Often this is simply not provided as there
> is nothing useful to be done.
>
> update_scan_mode -> get the scan mode set up right for all the buffers
> being feed by the iio_push_to_buffers calls.
>
> postenable -> Actually start the flow of data now all the flags are
> lined up to say we are enabled.  So in a typical triggered-buffer
> case call iio_trigger_attach_poll_func
>

Usually our drivers use prenable() for starting the data flow
and postdisable() to stop it.

Do you think it is a mistake?
Or acceptable?

>
> For the disable side:
> predisable unwinds postenable and postdisable typically unwinds
> preenable.
>

Yes, that's clear.

Regards,
Arm