Hi Boris,
On 30/10/2020 10:08, Boris Brezillon wrote:
The "propagate output flags" and soon to be added "use timing->input_flags if present" logic should only be used as a fallback for bridges that do not support dynamic bus format/flags negotiation IMHO. Ideally we'd want to convert all bridges to do this dynamic bus format/flags negotiation and get rid of timings->input_bus_flags once this is done, but that's likely to take time. So, if your driver implements the ->atomic_check() hook and needs specific input flags, I'd recommend setting the input flags there instead of specifying it through timings->input_bus_flags.
What is bus flags negotiation? Don't we have negotiation only for bus formats? Bus flags are just set, and the previous bridge in the chain has to use those flags.
Or do you just refer to setting the bus flags dynamically in atomic_check, versus static in input_bus_flags?
Tomi