Subject: [PATCH V7 1/4] Documentation/devicetree/bindings: b850v3_lvds_dp

From: [email-masked] (Laurent Pinchart)
Date: Tue, 10 Jan 2017 23:04:58 +0200

Hi Peter,

On Saturday 07 Jan 2017 01:29:52 Peter Senna Tschudin wrote:
> On 04 January, 2017 21:39 CET, Rob Herring wrote:
> > On Tue, Jan 3, 2017 at 5:34 PM, Peter Senna Tschudin wrote:
> >> On 03 January, 2017 23:51 CET, Rob Herring <[email-masked]> wrote:
> >>> On Sun, Jan 01, 2017 at 09:24:29PM +0100, Peter Senna Tschudin wrote:
> >>>> Devicetree bindings documentation for the GE B850v3 LVDS/DP++
> >>>> display bridge.
> >>>> 
> >>>> Cc: Martyn Welch <[email-masked]>
> >>>> Cc: Martin Donnelly <[email-masked]>
> >>>> Cc: Javier Martinez Canillas <[email-masked]>
> >>>> Cc: Enric Balletbo i Serra <[email-masked]>
> >>>> Cc: Philipp Zabel <[email-masked]>
> >>>> Cc: Rob Herring <[email-masked]>
> >>>> Cc: Fabio Estevam <[email-masked]>
> >>>> Signed-off-by: Peter Senna Tschudin <[email-masked]>
> >>>> ---
> >>>> There was an Acked-by from Rob Herring <[email-masked]> for V6, but
> >>>> I changed the bindings to use i2c_new_secondary_device() so I
> >>>> removed it from the commit message.
> >>>> 
> >>>>  .../devicetree/bindings/ge/b850v3-lvds-dp.txt      | 39 ++++++++++++++
> >>> Generally, bindings are not organized by vendor. Put in
> >>> bindings/display/bridge/... instead.
> >> 
> >> Will change that.
> >> 
> >>>>  1 file changed, 39 insertions(+)
> >>>>  create mode 100644
> >>>>  Documentation/devicetree/bindings/ge/b850v3-lvds-dp.txt
> >>>> 
> >>>> diff --git a/Documentation/devicetree/bindings/ge/b850v3-lvds-dp.txt
> >>>> b/Documentation/devicetree/bindings/ge/b850v3-lvds-dp.txt new file
> >>>> mode 100644
> >>>> index 0000000..1bc6ebf
> >>>> --- /dev/null
> >>>> +++ b/Documentation/devicetree/bindings/ge/b850v3-lvds-dp.txt
> >>>> @@ -0,0 +1,39 @@
> >>>> +Driver for GE B850v3 LVDS/DP++ display bridge
> >>>> +
> >>>> +Required properties:
> >>>> +  - compatible : should be "ge,b850v3-lvds-dp".
> >>> 
> >>> Isn't '-lvds-dp' redundant? The part# should be enough.
> >> 
> >> b850v3 is the name of the product, this is why the proposed name. What
> >> about, b850v3-dp2 dp2 indicating the second DP output?
> >
> > Humm, b850v3 is the board name? This node should be the name of the bridge
> > chip.
>
> From the cover letter:
> 
> -- // --
> There are two physical bridges on the video signal pipeline: a STDP4028(LVDS
> to DP) and a STDP2690(DP to DP++).  The hardware and firmware made it
> complicated for this binding to comprise two device tree nodes, as the
> design goal is to configure both bridges based on the LVDS signal, which
> leave the driver powerless to control the video processing pipeline. The
> two bridges behaves as a single bridge, and the driver is only needed for
> telling the host about EDID / HPD, and for giving the host powers to ack
> interrupts. The video signal pipeline is as follows:
> 
>   Host -> LVDS|--(STDP4028)--|DP -> DP|--(STDP2690)--|DP++ -> Video output
> -- // --

You forgot to prefix your patch series with [HACK] ;-)

How about fixing the issues that make the two DT nodes solution difficult ? 
What are they ?

-- 
Regards,

Laurent Pinchart