On Wed, Feb 01, 2023 at 09:23:56AM +0900, FUKAUMI Naoki wrote: > hi, > > I'm trying this patch series with 6.1.x kernel. it works fine on rk356x > based boards (ROCK 3), but it has a problem on rk3399 boards (ROCK 4). > > on rk3399 with this patch, I can see large noise area (about one third right > side of the screen) at 4k@30. 1080p works fine as same as before. > > can someone reproduce this problem on rk3399? Ok, I could easily reproduce the problem here. The RK3399 has two VOPs, vopb(ig) and vopl(ittle). Only the former can do 4k@30 while the latter can only do 1080p. Unfortunately vopl is used by default. We can force using vopb by disabling vopl in the device tree and get a good 4k@30 picture then. The other possibility I found is to use the other CRTC with modetest. I have no idea how we could set the default to vopb. I guess a first step would be to limit the maximum resolution of vopl to what the hardware can do. We would likely end up with 1080p by default then for the applications. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
