drm/bridge: Synopsys DW-HDMI bridge driver for the Ingenic JZ4780 (was Re: Specialising the Synopsys DW-HDMI bridge driver for the Ingenic JZ4780)

[H. Nikolaus Schaller]

Hi Ezequiel,

> Am 24.08.2020 um 19:38 schrieb Ezequiel Garcia <ezequiel at vanguardiasur.com.ar>:
> 
> On Mon, 24 Aug 2020 at 13:05, H. Nikolaus Schaller <hns at goldelico.com> wrote:
>> 
>> Hi Ezequiel,
> 
> The fix is just re-organizing the code a bit. Just pushed a possible
> fix for that (following the IPU handling by Paul Cercueil),
> please feel free to test this:
> 
> https://gitlab.collabora.com/linux/0day/-/commits/jz4780-drm-hdmi-module-fix-v5.9-rc2

Works well (after doing a minor fix to the CI20 defconfig)!

> 
> FWIW, my test setup uses mainline vanilla U-Boot v2020.07.
> The kernel is loaded via TFTP. Debian mipsel is mounted via NFS
> (which means dm9000 works). I'm testing with weston and modetest.
> 
> Note that enabling DRM_INGENIC_IPU will make the driver
> fail to load, as the IPU is not optional (and not present on ci20.dts).
> A minor thing to fix.
> 
> Cheers,
> Ezequiel
> 
>> And it seems to differ significantly from what Paul has developed recently
>> to make it work. It seems to be quite lucky that we have a working setup now :)
>> 
>>> Nikolaus, Paul: Do you have plans to submit these?
>> 
>> Yes, as soon as we are sure that it works (and when it doesn't).
>> 
>> But thanks to your work it is now much easier to improve things, since we
>> are no longer looking for a break-through but just have to avoid regressions.
>> 
>>> If not, I'll be happy to get them out the door for review.
>> 
>> Let it mature a little first and have it tested on more setups and rebased
>> to mainline v5.9-rc2 :)


> Am 24.08.2020 um 23:11 schrieb Paul Cercueil <paul at crapouillou.net>:
> 
> DRM drivers follow their own schedule, you should rebase to drm-misc-next instead.
> 

With the comment from Paul, I think it is best if you push them for review.

My patch set based on v5.9-rc2 is here (including one EFUSE patch which I have
included only for making my Ethernet interface work for testing):

https://git.goldelico.com/?p=letux-kernel.git;a=shortlog;h=refs/heads/letux/jz4780-hdmi-v5

Please take it, do the required squashes and rebasing and post them for discussion to the
appropriate lists.

BR and thanks for this great break through,
Nikolaus