From: Robert Jarzmik <robert.jarzmik@free.fr>
To: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Michael Grzeschik <m.grzeschik@pengutronix.de>,
Linux Media Mailing List <linux-media@vger.kernel.org>,
p.wiesner@phytec.de
Subject: Re: [PATCH 02/20] mt9m111: init chip after read CHIP_VERSION
Date: Sat, 31 Jul 2010 22:36:52 +0200 [thread overview]
Message-ID: <874off1j8b.fsf@free.fr> (raw)
In-Reply-To: <Pine.LNX.4.64.1007312157200.16769@axis700.grange> (Guennadi Liakhovetski's message of "Sat\, 31 Jul 2010 22\:09\:48 +0200 \(CEST\)")
Guennadi Liakhovetski <g.liakhovetski@gmx.de> writes:
> On Fri, 30 Jul 2010, Michael Grzeschik wrote:
>
>> Moved mt9m111_init after the chip version detection passage: I
>> don't like the idea of writing on a device we haven't identified
>> yet.
>
> In principle it's correct, but what do you do, if a chip cannot be probed,
> before it is initialised / enabled? Actually, this shouldn't be the case,
> devices should be available for probing without any initialisation. So, we
> have to ask the original author, whether this really was necessary,
> Robert?
Michael is right I think.
According to the specification, even before the reset, the control registers can
be read, and they'll return their current values, which can be weird before
reset, excepting the CHIP_VERSION which is hard coded.
Therefore I think Michael is right by reading chip version before doing the
reset, and I ack this patch.
Cheers.
--
Robert
next prev parent reply other threads:[~2010-07-31 20:37 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-30 14:53 [PATCH 00/20] MT9M111/MT9M131 Michael Grzeschik
2010-07-30 14:53 ` [PATCH 01/20] mt9m111: Added indication that MT9M131 is supported by this driver Michael Grzeschik
2010-07-31 19:49 ` Guennadi Liakhovetski
2010-07-31 20:10 ` Robert Jarzmik
2010-07-31 20:16 ` Guennadi Liakhovetski
2010-07-31 20:28 ` Robert Jarzmik
2010-07-30 14:53 ` [PATCH 02/20] mt9m111: init chip after read CHIP_VERSION Michael Grzeschik
2010-07-31 20:09 ` Guennadi Liakhovetski
2010-07-31 20:36 ` Robert Jarzmik [this message]
2010-07-30 14:53 ` [PATCH 03/20] mt9m111: register cleanup hex to dec bitoffset Michael Grzeschik
2010-07-31 20:40 ` Robert Jarzmik
2010-07-30 14:53 ` [PATCH 04/20] mt9m111: added new bit offset defines Michael Grzeschik
2010-07-31 20:44 ` Robert Jarzmik
2010-07-30 14:53 ` [PATCH 05/20] mt9m111: added default row/col/width/height values Michael Grzeschik
2010-07-31 20:25 ` Guennadi Liakhovetski
2010-07-30 14:53 ` [PATCH 06/20] mt9m111: changed MAX_{HEIGHT,WIDTH} values to silicon pixelcount Michael Grzeschik
2010-07-31 20:51 ` Robert Jarzmik
2010-07-30 14:53 ` [PATCH 07/20] mt9m111: changed MIN_DARK_COLS to MT9M131 spec count Michael Grzeschik
2010-07-30 14:53 ` [PATCH 08/20] mt9m111: cropcap use defined default rect properties in defrect Michael Grzeschik
2010-07-30 14:53 ` [PATCH 09/20] mt9m111: cropcap check if type is CAPTURE Michael Grzeschik
2010-07-30 14:53 ` [PATCH 10/20] mt9m111: rewrite make_rect for positioning in debug Michael Grzeschik
2010-08-01 9:33 ` Guennadi Liakhovetski
2010-07-30 14:53 ` [PATCH 11/20] mt9m111: added mt9m111 format structure Michael Grzeschik
2010-08-01 16:48 ` Guennadi Liakhovetski
2010-07-30 14:53 ` [PATCH 12/20] mt9m111: s_crop add calculation of output size Michael Grzeschik
2010-08-01 19:38 ` Guennadi Liakhovetski
2010-07-30 14:53 ` [PATCH 13/20] mt9m111: s_crop check for VIDEO_CAPTURE type Michael Grzeschik
2010-07-30 14:53 ` [PATCH 14/20] mt9m111: added reg_mask function Michael Grzeschik
2010-07-30 14:53 ` [PATCH 15/20] mt9m111: rewrite setup_rect, added soft_crop for smooth panning Michael Grzeschik
2010-07-30 14:53 ` [PATCH 16/20] mt9m111: added more supported BE colour formats Michael Grzeschik
2010-07-30 14:53 ` [PATCH 17/20] mt9m111: rewrite set_pixfmt Michael Grzeschik
2010-07-30 14:53 ` [PATCH 18/20] mt9m111: make use of testpattern in debug mode Michael Grzeschik
2010-07-30 14:53 ` [PATCH 19/20] mt9m111: try_fmt rewrite to use preset values Michael Grzeschik
2010-07-30 14:53 ` [PATCH 20/20] mt9m111: s_fmt make use of try_fmt Michael Grzeschik
2010-07-30 15:38 ` [PATCH 00/20] MT9M111/MT9M131 Guennadi Liakhovetski
2010-07-31 10:33 ` Robert Jarzmik
2010-08-02 10:35 ` Michael Grzeschik
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