[U-Boot] Regression due to 020bbcb "usb: hub: Power-cycle on root-hub ports"

[Marek Vasut]

Dear Stephen Warren,

> (Sorry to those on to/cc; I'm resending this so it goes to the correct
> mailing list)
> 
> Commit 020bbcb "usb: hub: Power-cycle on root-hub ports" causes a
> regression on Tegra systems.
> 
> The first time "usb start" is executed, it appears to work correctly.
> However, any subsequent time it is executed, it takes a long time, and
> eventually fails to find any USB devices.
> 
> This situation can happen quite often; for example, if the user forgets
> to plug in a USB device before booting, runs "usb start", realizes that,
> then plugs it in and runs "usb start" again. This is compounded on at
> least one of the Tegra boards, since CONFIG_PREBOOT is set to "usb
> start" on systems (laptops/clamshells) which have built-in USB keyboards.
> 
> If I simply revert this patch, then everything works again. (Yes,
> reverting requires fixing a small merge conflict.)
> 
> Do you have any idea what the problem can be? I'm tempted to simply ask
> for the patch to be reverted since it causes a regression.
> 
> Thanks for any idea how to fix this!

BUMP? Vivek, any ideas? Otherwise I'm reverting this.

Best regards,
Marek Vasut