Re: [PATCH 1/3] iio: imu: adis: add doc-string for 'adis' struct

From: "Ardelean, Alexandru" <alexandru.Ardelean@analog.com>
To: "jic23@kernel.org" <jic23@kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>
Subject: Re: [PATCH 1/3] iio: imu: adis: add doc-string for 'adis' struct
Date: Fri, 21 Feb 2020 16:51:37 +0000	[thread overview]
Message-ID: <e39d77b4115a2ce3e0483199d32f849623c3aa90.camel@analog.com> (raw)
In-Reply-To: <20200221161428.188e1532@archlinux>

On Fri, 2020-02-21 at 16:14 +0000, Jonathan Cameron wrote:
> On Fri, 21 Feb 2020 15:59:35 +0000
> "Ardelean, Alexandru" <alexandru.Ardelean@analog.com> wrote:
> 
> > On Fri, 2020-02-21 at 13:11 +0000, Jonathan Cameron wrote:
> > > On Fri, 21 Feb 2020 13:49:41 +0200
> > > Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
> > >   
> > > > This change adds a doc-string for the 'adis' struct. It details the
> > > > fields
> > > > and their roles.
> > > > 
> > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> > > > ---
> > > >  include/linux/iio/imu/adis.h | 14 ++++++++++++++
> > > >  1 file changed, 14 insertions(+)
> > > > 
> > > > diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
> > > > index ac7cfd073804..0787a3aabd05 100644
> > > > --- a/include/linux/iio/imu/adis.h
> > > > +++ b/include/linux/iio/imu/adis.h
> > > > @@ -73,6 +73,20 @@ struct adis_data {
> > > >  	bool has_paging;
> > > >  };
> > > >  
> > > > +/**
> > > > + * struct adis - ADIS device instance data
> > > > + * @spi: Reference to SPI device which owns this ADIS IIO device
> > > > + * @trig: IIO trigger object data
> > > > + * @data: ADIS chip variant specific data
> > > > + * @burst: ADIS burst transfer information
> > > > + * @state_lock: Lock used by the device to protect state
> > > > + * @msg: SPI message object
> > > > + * @xfer: SPI transfer objects to be used for a @msg
> > > > + * @current_page: Some ADIS devices have registers, this selects
> > > > current
> > > > page
> > > > + * @buffer: Data buffer for information read from the device
> > > > + * @tx: Cacheline aligned TX buffer for SPI transfers
> > > > + * @rx: Cacheline aligned RX buffer for SPI transfers  
> > > 
> > > This last one isn't true..   
> > 
> > Oh right.
> > I noticed this at some point, then forgot about it.
> > [ The "joys" of multi-tasking; sorry about it :) ]
> > I guess I should also add a patch in this series making it cacheline-
> > aligned.
> > I don't see a reason why not-to [unless I am misunderstanging something]
> No.  The code is fine.  The purpose of the cacheline stuff is to ensure
> no other data ends up in the same cacheline and might be changed in parallel
> with the spi dma taking place.   You only need to force it for the first
> element when you have 2 buffers like this.
> 
> So you need to update the comment in this patch to say something less
> specific.
> Perhaps
> 
> @tx: DMA safe TX buffer for SPI transfers
> @rx: DMA safe RX buffer for SPI transfers.
> 

Sounds good to me.

Thanks
Alex

> Thanks,
> 
> Jonathan
> 
> > 
> > >   
> > > > + */
> > > >  struct adis {
> > > >  	struct spi_device	*spi;
> > > >  	struct iio_trigger	*trig;  