On 25/09/2020 21:36, Arnaud Patard (Rtp) wrote: > This patchset add support for the rk3399 edp. It has been tested on the > pinebook > pro devices. The only missing part is a hack used to get stable edp output > after > a warn reset, which is possibly specific to this device. I'm not sure if it's > suitable > for merge. > > The changes have been written by studying the linux code, since I didn't find > any > manual for theses part of the RK3399 SoC. > > On the linux kernel side, on recent kernels, it needs commit "pwm: rockchip: > Keep enabled PWMs > running while probing" otherwise the pinebook pro will freeze when probing > the display. > > The kernel is also randomly failing to display something on my device. When > this > occurs, the kernel has this following message: > rockchip-pm-domain ff310000.power-management:power-controller: failed to set > idle on domain 'pd_vopl', val=0 > I've yet to find what's the issue.
I've been trying to test your patches on a rk3399-gru-kevin with these patches and as a result I've posted some patches for cros_ec_pwm as a backlight [1], and have some yet-to-be-posted ones for kevin and bob because I don't truly know if they work [2]. (I don't even have the appropriate hardware to get a serial console / debug this board, thus the motivation to get the screen working). It should be possible for someone with a kevin or bob to tinker on my test branch and get more conclusive outcomes than I did, maybe even get everything fully working! [1] https://patchwork.ozlabs.org/project/uboot/list/?series=204353 [2] https://github.com/alpernebbi/u-boot/commits/rk3399-gru-kevin/wip Anyway, here's how it goes for me. I start from the Chrome OS firmware showing some white-background bitmap on the screen with the backlight enabled. I press CTRL+L to tell it to chainload my U-Boot build. I don't know if/how chainloading this way affects any of this. AFAICT, the firmware doesn't clear or turn off the backlight before doing so, because when VIDEO_ROCKCHIP_MAX_{X,Y}RES={3840,2160} the screen doesn't clear. I have to set {2400,1600} as it's the resolution of my panel. Maybe you should test this on Pinebook Pro as well, the defaults are {1920,1080} (same as its panel), but DISPLAY_ROCKCHIP_HDMI for example would change it. With those initial conditions I see the the screen progressively clearing to black then the backlight turns off after a while. I think the clearing part hints this patchset is at least doing something. I had also tried commenting out "enable-gpios" code in pwm_backlight.c (when I didn't really know how to turn it on properly), that results in the backlight turn on immediately after it turns off, where I see a small white artifact (?) on the mid-right part of the bottom of the screen, for a frame or so. Overall, I never see any content on the display and it's always black. Even unsetting CONFIG_SYS_WHITE_ON_BLACK doesn't change anything. Wish I could've been more helpful, but all this is as far as I could figure out right now.
