Re: [DVO][PATCH] drm/i915: Fall back to bit banging mode for DVO transmitter detection

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