i.mx6 video out in mainline

[Pushpal Sidhu]

On Tue, Oct 6, 2015 at 3:16 PM, Fabio Estevam <festevam at gmail.com> wrote:
> On Tue, Oct 6, 2015 at 6:52 PM, Pushpal Sidhu <psidhu at gateworks.com> wrote:
>> Hi All,
>>
>> I'm attempting to use a standard fb console (using the
>> imx6qdl-gw54xx.dtsi), but I find that it only draws to the 1024x768p
>> portion of the screen. This is also true when running the userspace
>> tool fb-test.
>
> Looking at imx6qdl-gw54xx.dtsi I see you have a LVDS panel with
> 1024x768 resolution.
>
> I sent a patch that allows LDB and HDMI to work simultaneously:
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/imx6qdl-sabresd.dtsi?id=d28be499c45e6e16d7a042ce280eb872dc06952b
>
> Can you try to adapt it for imx6qdl-gw54xx.dtsi?
>
> If this still does not help your HDMI output, please try disabling the LVDS.

When I took your patch and adapted it for imx6qdl-gw54xx.dtsi, I found
that HDMI video out was slightly shifted to the left and resolution
remained at 1024x768p.

I also found that when I disabled DRM_IMX_LDB, HDMI out stopped
working altogether, though if I stripped out the ldb section in device
tree, the resolution comes back at 1080p (regardless of setting
DRM_IMX_LDB or not). There is definitely some strange interdependency
between lvds and hdmi here. Do you have an idea of where I should
start looking for this problem?

- Pushpal