I have a 8GB rock3a and I’m using a mainline 5.17 kernel. I can enable the rga in dtb with CounterPillow’s patch. But when I use gstreamer command gst-launch-1.0 videotestsrc ! video/x-raw,width=320,height=240 ! v4l2convert ! video/x-raw,width=640,height=480 ! autovideosink
, I get a green window. And I can see rga error:
rockchip-rga fdeb0000.rga: swiotlb buffer is full (sz: 393216 bytes), total 32768 (slots), used 6827 (slots)
After some search on internet, I found that other people using rockchip 4.19 also meet this issue: https://forum.odroid.com/viewtopic.php?f=211&t=44281&sid=8c3a1dedcc2e517ab52168e19f0b6970. I add “mem=4G” to my boot parameter and I can run the above gstreamer command with normal output. It seems that the rockchip rga2 driver is used for chips released before rk3568 which don’t have memory larger than 4GB.