From: Mark Jackson <mpfj@mimc.co.uk>
To: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>,
rtc-linux@googlegroups.com, lkml <linux-kernel@vger.kernel.org>,
spi-devel-general@lists.sourceforge.net
Subject: Re: [PATCH] Add Dallas DS1390 RTC chip
Date: Fri, 17 Oct 2008 19:57:29 +0100 [thread overview]
Message-ID: <48F8E019.20600@mimc.co.uk> (raw)
In-Reply-To: <200810170829.06699.david-b@pacbell.net>
David Brownell wrote:
> On Friday 17 October 2008, Mark Jackson wrote:
>>>> + /* Can tx_buf and rx_buf be equal? The doc in spi.h is not sure... */
>>>> + xfer.tx_buf = chip->tx_buf;
>>>> + xfer.rx_buf = chip->rx_buf;
>>> you use the same buffer a few functions below. either
>>> one way or the other. please investigate with the spi subsystem maintainer.
>> David,
>>
>> Just to double check (as per Alessandro's suggestion), is this okay use of the
>> spi buffers ?
>
> Yes. That comment deserves to be updated.
>
> SPI does bi-directional I/O, and the underlying controller
> should be able to just replace the contents of a buffer
> with a spi_transfer that uses the same rx and tx buffers.
Excellent. Thanks for the confirmation.
Regards
Mark
next prev parent reply other threads:[~2008-10-17 19:28 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <48F452BE.2030901@mimc.co.uk>
2008-10-14 8:17 ` [PATCH] Add Dallas DS1390 RTC chip Alessandro Zummo
2008-10-17 8:02 ` Mark Jackson
2008-10-17 15:29 ` David Brownell
2008-10-17 18:57 ` Mark Jackson [this message]
2008-10-07 13:44 Mark Jackson
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