[Intel-gfx] [PATCH 11/12] drm/i915: Check for invalid cloning earlier during modeset

[Maarten Lankhorst]

Op 08-06-16 om 15:27 schreef Ville Syrjälä:
> On Wed, Jun 08, 2016 at 02:15:25PM +0100, Chris Wilson wrote:
>> On Wed, Jun 08, 2016 at 01:41:46PM +0300, ville.syrjala at linux.intel.com wrote:
>>> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>>
>>> Move the encoder cloning check to happen earlier in the modeset. The
>>> main benefit will be that the debug output from a failed modeset will
>>> be less confusing as output_types can not indicate an invalid
>>> configuration during the later computation stages.
>>>
>>> For instance, what happened to me was kms_setmode was attempting one
>>> of its invalid cloning checks during which it asked for DP+VGA cloning
>>> on HSW. In this case the DP .compute_config() was executed after
>>> the FDI .compute_config() leaving the DP link clock (1.62 in this case)
>>> in port_clock, and then later the FDI BW computation tried to use that
>>> as the FDI link clock (which should always be 2.7). 1.62 x 2 wasn't
>>> enough for the mode it was trying to use, and so it ended up rejecting
>>> the modeset, not because of an invalid cloning configuration, but
>>> because of supposedly running out of FDI bandwidth. Took me a while
>>> to figure out what had actually happened.
>> Did it reject the 1.62 link clock when you simply removed the
>> check_encoder_cloning()? Just checking... :)
> Nope. The rejection only happened due to exceeding the max fdi lane
> count. I think I had a warn in there somewhere when I originally
> submitted the fdi==port_clock patch, but that apparently didn't
> survive into the version that eventually got merged.
>
For patch 1-11:

Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>