It's down to the implementation of the hardware and how/when it can insert command packets. One of the DSI controllers can't send command packets at all once they've switched to HS mode!Still wondering how the original driver works for others,
If you had longer blanking timings, then vc4 should have been able to send them, but as the sequencing isn't critical here, it's easier to change when you send them.
Lack of documentation/design meant that many other DSI host controllers had been setting up the mode and enabling the host controller in the mode_set hook, which is deprecated and isn't what that hook was meant to do.also regarding the missing "ctx->panel.prepare_prev_first=true" I had to add to the st7703_probe().
The *_prev_first flags were added by me to upstream, but there's still a load of bike-shedding over whether it solves the problem or not, so not all panel drivers have set it. Some folks are still debating it, but there seems to be a general lack of interest to fixing it.
Statistics: Posted by 6by9 — Wed Nov 20, 2024 1:25 pm