[PATCH v2 1/2] usb: hub: allow to increase HUB_DEBOUNCE_TIMEOUT

[Marek Vasut]

On 9/9/22 11:45, Patrick Delaunay wrote:
> Add a new CONFIG_USB_HUB_DEBOUNCE_TIMEOUT to increase the
> HUB_DEBOUNCE_TIMEOUT value, for example to 2s because some usb device
> needs around 1.5s or more to make the hub port status to be
> connected steadily after being powered off and powered on.
> 
> This 2s value is aligned with Linux driver and avoids to configure
> "usb_pgood_delay" as a workaround for connection timeout on
> some USB device; normally the env variable "usb_pgood_delay" is used
> to delay the first query after power ON and thus the device answer,
> but this variable not used to increase the connection timeout delay.

I realized this has one problem -- what happens if you have multiple USB 
controllers in your system ? The answer is, all of them are affected by 
the increased delay, possibly even those which do not require the extra 
delay.

Would it be possible to configure this per-controller (or should this 
even be per-device?) in DT ? In fact, I wonder whether this is not 
becoming a Vbus regulator ramp-up time kind of delay here ?