Mode validation outside of connector or encoder (i.e. at CRTC or drm_driver level)

[Matt Sealey]

On Thu, Feb 16, 2012 at 9:51 AM, Adam Jackson <ajax at redhat.com> wrote:
> On Wed, 2012-02-15 at 22:43 -0600, Matt Sealey wrote:
>> Quick question; if I want to validate a mode given to me by a
>> connector/encoder as workable or not before I am going through the
>> code to actually set that mode, how would I do this?
>
> I think this is an API bug.  The crtc really should get a chance to do
> this.  If nothing else it would simplify existing drivers, since eg
> Intel gen3 wouldn't have to replicate the width>2048 check across every
> output type.

Yay I found a bug?!

Okay so a crtc helper func for mode_valid would probably be the way to go..

Now the big question; the only user of mode_valid that I see is
drm_helper_probe_single_connector_modes which has no "access" to the
crtc or crtc helpers right now. It does checking on maximums and
interlace/doublescan, should these eventually be passed to the crtc
for verification instead of having the connector actually do this?

It seems like a rather huge, messy API bug to fix at first glance..

-- 
Matt Sealey <matt at genesi-usa.com>
Product Development Analyst, Genesi USA, Inc.