Hi, On Wed, Apr 18, 2018 at 08:29:59PM +0200, Daniel Glöckner wrote: > The VBI instruction queue read pointer points outside the VBI instruction > queue and into the video y/packed CMDS (to 0x180000+0x11*4). The values > next to the iq rd ptr look ok. > > We only initialize the iq rd ptr to zero in cx88_sram_channel_setup and > then never touch it again. The hardware takes care of updating it. > Maybe cx88_sram_channel_setup is sometimes called for channel 24 while the > VBI risc engine is still running? for some reason I feel like buffer_queue in cx88-vbi.c should not be calling cx8800_start_vbi_dma as it is also called a few lines further down in start_streaming. Devin, can you check if it helps to remove that line and if VBI still works afterwards? Best regards, Daniel