[Intel-gfx] [PATCH 1/2] drm/i915: Detect SDVO-RGB before SDVO TV

[ykzhao]

On Mon, 2010-02-01 at 09:34 +0800, Zhenyu Wang wrote:
> On 2010.01.30 09:38:16 +0800, Fu Michael wrote:
> > >
> > > Why should what order the connectors get set up matter?  If it's supposed
> > > to matter, has this been tested in anything other than this guy's
> > > particular configuration to make sure that you're not regressing other
> > > picky encoders?
> > >
> > > If I had to take a wild guess, this would be another manifestation of
> > > the failure of the SDVO code to have a single encoder instance managing
> > > the multiple connectors attached to it, so the different connectors
> > > fight over the state of the encoder.
> > >   
> > actually it's not the code but the card in this case.
> > 
> 
> well, we need to fix our code to work with that SDVO behaivor..
> 
> > we have only one way to know what kind of monitor is attached to a sDVO 
> > card, that is to send a command to it and read back response. For the 
> > card in this bug report, even though it only has VGA attached. It report 
> > all of its capabilities are connected, which apparently is not true. if 
> > we just pass that message up to user space, the bogus connection would 
> > mess up mode setting then, so technically, this is a patch in UMS that 
> > happen worked around it.
> 
> In my origin patch for UMS on multifunction SDVO support, SDVO connector
> info is updated in output detect and output name for randr is given massage
> to adjust for real output type. For SDVO KMS, we should split encoder/connector
> state based on device capability, and detect would check if connector type
> matches.

For the UMS mode, the output device name is handled in our driver. We
can make it easy to change its name and property. But in KMS mode, now
we will have no way to change its output name and property.

> 

But for the multi-functional SDVO card the multi connector are matched
to the same encoder. If we create more than one connector for the
multi-function card, we can choose which connector is used. But it is
very careful to consider the synchronization between multiple connector.
If only one connector is created, we will have to change the connector
type/id again.

Of course I will look at the realization of connector/encoder in
Radeon/NV and consider how to split the connector/encoder for our
driver.

Thanks.
	Yakui.

> > 
> > Such kind of multi-function sdvo card is rare. we don't have any, and we 
> > only see one bug report from community in our bugzilla as well.  I guess 
> > that's why UMS has been living with it fine for a long time.
> > 
> 
> UMS is fine with that as my note above. I think we do have a littlefall
> motherboard which has multi-function sdvo, that I used for SDVO TV enabling before.
> 
> 
> >  I guess if we want a decent fix for this, maybe our last hope is to see 
> > if VBT has any information to tell us not to bother with other type but 
> > just one kind of connector on this SDVO device. But I'm not sure if this 
> > would break other normal cards then, just in case a VBT is broken...
> 
> yeah, old platform usually won't have finally correct BIOS update.
>