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From: "Albrecht Dreß" <albrecht.dress-KvP5wT2u2U0@public.gmane.org>
To: joakim.tjernlund-SNLAxHN9vbcOP4wsBPIw7w@public.gmane.org
Cc: linuxppc-dev-mnsaURCQ41sdnm+yROfE0A@public.gmane.org,
	devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org,
	ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org,
	iws-lulEs6mt1IksTUYHLfqkUA@public.gmane.org
Subject: Re: [Patch v2 1/2] 5200/mpc: improve i2c bus error recovery
Date: Thu, 18 Feb 2010 10:09:23 +0100 (CET)	[thread overview]
Message-ID: <33411516.1266484163759.JavaMail.ngmail@webmail09.arcor-online.net> (raw)
In-Reply-To: <OF3D88A7A0.9A4F1639-ONC12576CE.002C0FB9-C12576CE.002CCBBB-SNLAxHN9vbcOP4wsBPIw7w@public.gmane.org>


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Hi Joakim:

> Does this reset sequence also send a START condition for every clock?

Please see the attached scan from a scope output, showing the first two out of the 9 sequences at 375 kHz (that's what the 5200's divider makes from 400 kHz requested).  Resolution is 2us/div and 1V/div for both signals.  The waveform itself for each of the 9 sequences is exactly the same we had before with the old solution, just the timing is faster and adjusted to the ii2c clock, i.e. the /relative/ waveforms look identical for slower clocks.

Any insight if this is *really* correct would be great, as I'm not an i2c expert.  I can only say it reliably fixes the bus hangs I saw!

Thanks,
Albrecht.

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  parent reply	other threads:[~2010-02-18  9:09 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-17 18:59 [Patch v2 1/2] 5200/mpc: improve i2c bus error recovery Albrecht Dreß
2010-02-17 20:10 ` Grant Likely
2010-02-18  8:09 ` Joakim Tjernlund
     [not found] ` <OF3D88A7A0.9A4F1639-ONC12576CE.002C0FB9-C12576CE.002CCBBB-SNLAxHN9vbcOP4wsBPIw7w@public.gmane.org>
2010-02-18  9:09   ` Albrecht Dreß [this message]
2010-02-18 12:33     ` Joakim Tjernlund
2010-02-18 13:23 ` Joakim Tjernlund
2010-05-05 22:09 ` Ira W. Snyder
2010-05-06 17:54   ` Albrecht Dreß
2010-05-06 18:06     ` Grant Likely
2010-05-16 17:47       ` Albrecht Dreß
2010-05-19 16:02         ` Grant Likely
2010-06-16 19:30           ` Albrecht Dreß
  -- strict thread matches above, loose matches on Subject: below --
2010-02-18 15:04 Albrecht Dreß
2010-02-18 17:14 ` Joakim Tjernlund
2010-02-18 17:41   ` Grant Likely
2010-02-18 18:07     ` Joakim Tjernlund
     [not found]   ` <OFC412BED7.5D5934A3-ONC12576CE.005D5F44-C12576CE.005EBE55-SNLAxHN9vbcOP4wsBPIw7w@public.gmane.org>
2010-02-18 18:45     ` Albrecht Dreß

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