[PATCH 02/21] drm: mxsfb: Use drm_panel_bridge

[Stefan Agner]

On 2020-03-23 22:38, Sam Ravnborg wrote:
> Hi Stefan.
> 
> On Mon, Mar 23, 2020 at 10:27:21PM +0100, Stefan Agner wrote:
>> On 2020-03-09 20:51, Laurent Pinchart wrote:
>> > Replace the manual connector implementation based on drm_panel with the
>> > drm_panel_bridge helper. This simplifies the mxsfb driver by removing
>> > connector-related code, and standardizing all pipeline control
>> > operations on bridges.
>> >
>> > A hack is needed to get hold of the connector, as that's our only source
>> > of bus flags and formats for now. As soon as the bridge API provides us
>> > with that information this can be fixed.
>>
>> This seems like a nice simplification.
>>
>> I gave this a go applied on today's drm-misc-next using a Colibri iMX7
>> (imx7d-colibri-emmc-eval-v3.dts device tree). This device makes use of
>> the simple panel driver. I get this when booting:
>>
>> [    2.976698] [drm] Supports vblank timestamp caching Rev 2
>> (21.10.2013).
>> [    2.983526] ------------[ cut here ]------------
>> [    2.988180] WARNING: CPU: 0 PID: 1 at
>> drivers/gpu/drm/bridge/panel.c:267 devm_drm_panel_bridge_add+0x25/0x28
> 
> ...
> 
> I think you hit one of the panels that does not yet specify a
> connector_type.
> 
> If this is the case, we should fix the definition in panel-simple.

Yes, this indeed the case, I used the "logictechno,lt161010-2nhc"
compatible string. Will get this fixed!

But I think its still worth defining a default in the driver as DPI is
what this IP outputs...

--
Stefan