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From: "\"David Müller (ELSOFT AG)\"" <d.mueller@elsoft.ch>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: [DVO][PATCH] drm/i915: Fall back to bit banging mode for DVO transmitter detection
Date: Fri, 19 Apr 2013 12:54:00 +0200	[thread overview]
Message-ID: <51712248.8010504@elsoft.ch> (raw)
In-Reply-To: <20130419091414.GS6169@phenom.ffwll.local>

Daniel Vetter wrote:
> On Fri, Apr 19, 2013 at 10:41:50AM +0200, "David Müller (ELSOFT AG)" wrote:
>> +		/* GMBUS NAK handling seems to be unstable, hence let the
>> +		 * transmitter detection run in bit banging mode for now.
>> +		 */
>> +		intel_gmbus_force_bit(i2c, true);
>> +
>> +		dvoinit = dvo->dev_ops->init(&intel_dvo->dev, i2c);
>> +
>> +		intel_gmbus_force_bit(i2c, false);
> 
> Shouldn't we keep the dvo i2c line in bit-banging mode always, i.e.
> restore gmbus mode only when dvo init failed?
> 
> I suspect that for fickle hw not just init will fail ...

As far as i can tell, the critical part is the NAK handling.

Dave

  reply	other threads:[~2013-04-19 10:54 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-19  8:41 [DVO][PATCH] drm/i915: Fall back to bit banging mode for DVO transmitter detection "David Müller (ELSOFT AG)"
2013-04-19  9:14 ` Daniel Vetter
2013-04-19 10:54   ` "David Müller (ELSOFT AG)" [this message]
2013-04-19 14:31     ` Daniel Vetter

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