From: Mark Brown <broonie@kernel.org>
To: Doug Anderson <dianders@chromium.org>
Cc: apronin@chromium.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-spi <linux-spi@vger.kernel.org>
Subject: Re: [PATCH 1/4] spi: Add option to wake a device by toggling CS
Date: Fri, 1 Jul 2016 19:17:08 +0200 [thread overview]
Message-ID: <20160701171708.GC6247@sirena.org.uk> (raw)
In-Reply-To: <CAD=FV=W8gt+xgsJ5pPz1uCXGubDHkOnXoDz0mq--cDvkdf-j9g@mail.gmail.com>
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On Fri, Jul 01, 2016 at 10:05:50AM -0700, Doug Anderson wrote:
> I'm curious why you you need a timer at all. Can't you just keep
> track of the jiffies that you last sent and do subtraction? ...or you
> could get even more accurate and use a ktime_t. That avoids a whole
> lot of synchronization / locking issues too...
Yeah, that'd be a lot better.
> Also: presumably you'll need to make sure that there's some margin in
> this whole thing. I'd imagine that if the timeout is 10000
> nanoseconds and you do the calculation and you last sent 9999
> nanoseconds ago then you might decide that the other side isn't asleep
> yet. ...but by the time the transfer starts it might be asleep...
Indeed.
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next prev parent reply other threads:[~2016-07-01 17:17 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-30 3:54 [PATCH 1/4] spi: Add option to wake a device by toggling CS apronin
2016-06-30 3:54 ` [PATCH 2/4] spi: Document " apronin
2016-06-30 7:12 ` Geert Uytterhoeven
2016-07-01 4:32 ` Doug Anderson
2016-06-30 3:54 ` [PATCH 3/4] spi: Add option to insert delay between transactions apronin
2016-07-01 4:44 ` Doug Anderson
2016-07-01 8:16 ` Mark Brown
2016-06-30 3:54 ` [PATCH 4/4] spi: Document " apronin
2016-06-30 7:12 ` Geert Uytterhoeven
2016-07-01 4:45 ` Doug Anderson
2016-07-01 4:23 ` [PATCH 1/4] spi: Add option to wake a device by toggling CS Doug Anderson
2016-07-01 8:21 ` Mark Brown
2016-07-01 17:05 ` Doug Anderson
2016-07-01 17:17 ` Mark Brown [this message]
2016-07-02 2:02 ` Andrey Pronin
2016-07-01 8:02 ` Mark Brown
2016-07-02 1:45 ` Andrey Pronin
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