On Wed, May 15, 2019 at 08:08:57AM -0700, Vasily Khoruzhick wrote: > On Wed, May 15, 2019 at 12:32 AM Torsten Duwe <duwe@xxxxxx> wrote: > > > > It does comply with the bindings. The ports are all optional. > > As far as DT is concerned, the signal path ends here. This is also the > > final component _required_ to get the Linux kernel DRI up and running. > > Ugh, then bindings should be fixed. It's not optional. It may work if > bootloader enables power for you, but it won't if you disable display > driver in u-boot. I double-checked. On the Teres-I, mentioning the panel _is_ optional. PD23 powers down panel and backlight as much as possible, see 24bd5d2cb93bc arm64: dts: allwinner: a64: teres-i: enable backlight (currently only in Maxime's repo) and the Teres-I schematics... And the driver in your repo neatly guards all accesses with "if (anx6345->panel)" -- good! But I found the Vdds are required, so I added them as such. > I guess you're testing it with older version of anx6345. Newer version > that supports power management [1] needs startup delay for panel. > Another issue that you're seeing is that backlight is not disabled on > DPMS events. All in all, you need to describe panel in dts. > > [1] https://github.com/anarsoul/linux-2.6/commit/2fbf9c242419c8bda698e8331a02d4312143ae2c > > Should I also have added a Tested-by: ? ;-) > > I don't have Teres, so I haven't tested these. *I* have one, and this works. I'll retest with your newer driver, just in case. Nonetheless, the changes in this series should be fine. Sending out v2 in a moment... Torsten