[Intel-gfx] [PATCH 1/2] drm/i915/crt: Remove 0xa0 probe for CRT

[Keith Packard]

On Mon,  4 Apr 2011 07:26:44 +0100, Chris Wilson <chris at chris-wilson.co.uk> wrote:

> Following the fix to reset the GMBUS controller after a NAK, we finally
> utilize the 0xa0 probe for a CRT connection. And discover that it is
> useless as it simply detects the presence of the controller and not the
> actual monitor. Given that we already probe 0x50 prior to performing the
> EDID retrieval, we can simply remove the redundant probe to 0xa0.

I don't understand -- are you saying that there is additional hardware
somewhere in the machine responding to I2C transactions on the monitor's
DDC bus?

And if so, how was this extra transaction breaking things? The GMBUS
reset patch should only have an effect when there are failed
transactions, not successful ones, and then it should only cause future
transactions to fail, not succeed. Besides, the 0xA0 transaction looks
like the first one on the bus.

-- 
keith.packard at intel.com
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