From: pavel@ucw.cz (Pavel Machek)
Date: Sun, 18 Apr 2010 16:11:26 +0200
Subject: [PATCH 2/3] i2c/pxa: only define 'blue_murder'-function if
	DEBUG is #defined
In-Reply-To: <20100418140548.GC21364@pengutronix.de>
References: <20100224110044.GB15181@pengutronix.de>
	<1267009306-17227-2-git-send-email-u.kleine-koenig@pengutronix.de>
	<20100228155502.GB16745@n2100.arm.linux.org.uk>
	<20100418132251.GB21364@pengutronix.de>
	<20100418134502.GA15452@n2100.arm.linux.org.uk>
	<20100418140548.GC21364@pengutronix.de>
Message-ID: <20100418141126.GA15193@elf.ucw.cz>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Sun 2010-04-18 16:05:48, Wolfram Sang wrote:
> > > I am sure this is safe because we have retries. The eeprom driver first tries
> > > to write data without a delay, because EEPROMs often have buffers. Once the
> > > buffers are full, the chip will not answer to the next write request which will
> > > result in a timeout for this write request. This is expected, so it will be
> > > retried after some delay. Something like -EBUSY. Only if another "outer"
> > > timeout passed after some retries, then we have a problem and this should be
> > > user visible. But the timeout for the write request is nothing exceptional and
> > > the user doesn't need to be informed about it, especially not in this detail.
> > > This is what the patch is addressing.
> > 
> > And what if it's not an EEPROM that you're talking to?
> 
> That's up to the corresponding driver. The driver is still notified via the
> return value how many i2c-messages could be transmitted. If this is not equal
> to what the driver intended, then it can decide to retry or notify the user.
> And that is the apropriate level. Doing all this printout at the bus-driver
> level is only interesting for developers. Users are frightened by the "timeout"
> in their logs although everything might be as expected. A bus driver can't
> know.

I guess expected conditions should not trigger log spam...?
									Pavel
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