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From: Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>
To: Alexander Kochetkov <al.kochet-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: balbi-l0cyMroinI0@public.gmane.org,
	linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>,
	Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
Subject: Re: [PATCH 2/2] i2c: omap: fix "Too much work in one IRQ" irq handling
Date: Tue, 18 Nov 2014 10:38:27 -0600	[thread overview]
Message-ID: <20141118163827.GA6179@saruman> (raw)
In-Reply-To: <5D39428D-F359-4F04-8ACC-D607011B88B9-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

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On Tue, Nov 18, 2014 at 07:31:44PM +0300, Alexander Kochetkov wrote:
> 
> > Still, as of now we can't consider what Alexander mentions a bug. Good
> > to get it sorted out, but not -rc material.
> > 
> 
> Actually, I focused on fixing issues then i2c-omap acts as master in a
> multi master environment.

but that's not supported either. If you wanna do that, then go through
the TRM and implement what's missing. Then give a good commit log
explaining the issues and how you solved them :-)

Still not -rc material :-)

> And must say, that current linux/mainline driver work perfectly with
> minor fixes.

that's good to know. I know some folks still have a few hick ups. The IP
isn't all that great, I'm afraid.

> I could take a look how to switch the driver into mixed master/slave
> mode, but later.
> 
> Sad to say, I encountered undocumented i2c- hardware issue.
> In short: BB-bit doesn't reflect I2C-bus state after soft reset if SDA
> or SCL line was low during reset until i2c-controller again detect
> START or STOP condition on the wire.

this is another of those which really deserves a mention in code comment
or commit log :-)

> More over, if SDA was low during reset, than next submitted transfer
> will not start ("controller timeout"), if SCL was low during reset,
> than next submitted transfer will start and corrupt signals on wire :(

another thing to add as comment to code :-)

> I'm checking it now. And going to post results to ti forum.
> 
> BB-bit reflect I2C-bus state, between power-down/power-up modes.

alright, thanks.

-- 
balbi

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  parent reply	other threads:[~2014-11-18 16:38 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-15  1:20 [PATCH 1/2] i2c: omap: fix NACK and Arbitration Lost irq handling Alexander Kochetkov
     [not found] ` <1416014452-6712-1-git-send-email-al.kochet-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-11-15  1:20   ` [PATCH 2/2] i2c: omap: fix "Too much work in one IRQ" " Alexander Kochetkov
     [not found]     ` <1416014452-6712-2-git-send-email-al.kochet-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-11-15  1:48       ` Felipe Balbi
2014-11-15  2:37         ` Alexander Kochetkov
2014-11-15  3:47           ` Felipe Balbi
2014-11-15  3:53             ` Felipe Balbi
2014-11-15  5:42               ` Alexander Kochetkov
2014-11-16 15:45                 ` Felipe Balbi
2014-11-17 14:41                   ` Wolfram Sang
2014-11-18 16:00                     ` Felipe Balbi
2014-11-18 16:12                       ` Wolfram Sang
2014-11-20 16:38                         ` Alexander Kochetkov
     [not found]                           ` <2DED62C3-7C54-49E0-A39B-F68D5DAC66B1-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-11-20 16:43                             ` Wolfram Sang
2014-11-18 16:31                       ` Alexander Kochetkov
     [not found]                         ` <5D39428D-F359-4F04-8ACC-D607011B88B9-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-11-18 16:38                           ` Felipe Balbi [this message]
2014-11-15  1:43   ` [PATCH 1/2] i2c: omap: fix NACK and Arbitration Lost " Felipe Balbi
     [not found]     ` <2159E044-9130-410D-905B-B941408DCDCD@gmail.com>
     [not found]       ` <2159E044-9130-410D-905B-B941408DCDCD-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-11-15  2:48         ` Alexander Kochetkov

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