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From: Alexander Sverdlin <alexander.sverdlin-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
To: ext Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
Cc: Nicholas Mc Guire
	<hofrat-Q945KHDl0DbYtjvyW6yDsg@public.gmane.org>,
	Anders Berg <anders.berg-1wcpHE2jlwO1Z/+hSey0Gg@public.gmane.org>,
	"linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Wilshire Jay
	<jay.wilshire.ext-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>,
	Lawnick Michael
	<michael.lawnick-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH] i2c: axxia: Add bus recovery functionality
Date: Wed, 13 May 2015 10:26:45 +0200	[thread overview]
Message-ID: <55530AC5.1060806@nokia.com> (raw)
In-Reply-To: <20150512191211.GC4449-oo5tB6JMkjKRinMKxDlMNPwbnWRJjS81@public.gmane.org>

Hi!

On 12/05/15 21:12, ext Wolfram Sang wrote:
>> Use recovery framework and implement bus recovery using "Bus Monitor"
>> > register. Tests show that shortening SCL to GND results in "completion"
>> > timeout with "BUSY" bit still set. So initiate recovery in case of generic
>> > timeout and "Arbitration Lost" condition.
> So, how could you verify in this setup if the recovery actually worked?

Yes, it's tested with jumpers and oscilloscope on a custom Axxia AXM5508-based board.
9 CLK pulses are there and it's also jumping out of recovery if SDA is not low any more.

>> > +	switch (idev->msg_err) {
>> > +	case -ETIMEDOUT:
>> > +	case -EAGAIN:
>> > +		i2c_recover_bus(&idev->adapter);
>> > +	}
>> > +
> Doesn't look right. -EAGAIN means arbitration lost which is not a
> condition to reset the bus in a multi-master setup.

I'll resend with only -ETIMEDOUT triggering the recovery.

-- 
Best regards,
Alexander Sverdlin.

      parent reply	other threads:[~2015-05-13  8:26 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-28 12:20 [PATCH] i2c: axxia: Add bus recovery functionality Alexander Sverdlin
     [not found] ` <553F7B11.5000204-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
2015-05-12 19:12   ` Wolfram Sang
     [not found]     ` <20150512191211.GC4449-oo5tB6JMkjKRinMKxDlMNPwbnWRJjS81@public.gmane.org>
2015-05-13  6:19       ` Michael Lawnick
     [not found]         ` <5552ED0F.7000200-Mmb7MZpHnFY@public.gmane.org>
2015-05-13  6:55           ` Uwe Kleine-König
     [not found]             ` <20150513065549.GG28888-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2015-05-13  7:20               ` Michael Lawnick
     [not found]                 ` <5552FB50.4000409-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
2015-05-13  7:54                   ` Uwe Kleine-König
2015-05-13  8:26       ` Alexander Sverdlin [this message]

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