On Sat Apr 8, 2023 at 9:07 AM CEST, Jernej Škrabec wrote: > Dne sreda, 05. april 2023 ob 14:34:11 CEST je Roman Beranek napisal(a): > > While simply forbidding the video0-2x mux option seems > > to me as the right way to go because there's not much use for it with > > non-DSI interfaces either besides the opportunity to power pll-mipi > > down, I'd like to run by you first. > > It's been a long time since I looked at A64 HDMI clocks, but IIRC, pll-video0 > is the only useful source for HDMI PHY (as opposed to HDMI controller.) > So question remains how to properly support both displays at the same time. > Correct. > Have you ever tried to make HDMI and DSI work at the same time? This is one of > issues of the PinePhone IIUC. > Yes, I have. Prusa3D's SL1 printer, on which I previously worked on, uses both outputs simultaneously. I had encountered the same reparenting problem back then but since I hadn't been able to identify it, I resorted to fiddling with the DSI pixelclock until it worked. DSI & HDMI co-existence is yet another reasoni though for forbidding the pll-video-2x parent. megi's kernel includes Mr. Zheng's commit which does the same. <https://github.com/megous/linux/commit/7374d57> Best wishes Roman Beranek
