[drm] *ERROR* mstb 0000000057b5b857 port 1: DPCD read on addr 0x4b0 for 1 bytes NAKed

[Jocelyn Falempe]

On 17/02/2022 19:15, Lyude Paul wrote:
> Hi! Sorry for the late reply, I had to take some time off work unexpectedly.
> This is normal (although not great TBH, I'm not sure we should be printing an
> error message for that), it's the result of fwupd trying to probe the MST hub
> to see if it's a specific Dell dock that can receive updates over DP aux, but
> it's not smart enough to know it doesn't need to poke the DP aux ranges of
> downstream branches or non-MST ports in general.
I think MST topology is not exposed to userspace, so it would be hard 
for fwupd to be smarter than that.

> 
> Would definitely accept patches to make this a non-error, or at least make
> this a non-error when the read/writes come from userspace

I will try to provide a patch for this.

Thanks,

-- 

Jocelyn