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

[Marek Vasut]

Dear Stephen Warren,

> On 07/08/2013 07:25 AM, Vivek Gautam wrote:
> > On Mon, Jul 8, 2013 at 6:33 PM, Marek Vasut <marex at denx.de> wrote:
> >>> On Mon, Jul 1, 2013 at 10:11 PM, Stephen Warren <swarren at wwwdotorg.org> 
wrote:
> >>>> On 07/01/2013 07:49 AM, Vivek Gautam wrote:
> >>>>> On Sun, Jun 30, 2013 at 10:08 PM, Marek Vasut <marex at denx.de> wrote:
> >>>>>>> (Sorry to those on to/cc; I'm resending this so it goes to the
> >>>>>>> correct mailing list)
> >>>>> 
> >>>>> Dear Stephen,
> >>>>> sorry for the delay in responding to this.
> >>>>> 
> >>>>>>> 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.
> 
> ...
> 
> >>>>>> BUMP? Vivek, any ideas? Otherwise I'm reverting this.
> 
> ...
> 
> >>>>> There's one BUG that i could see in " 0bf796f " commit.
> >>>>> Now that we parallelized the sequence to power cycle ports, so if
> >>>>> get_port_status for any port failed,
> >>>>> it returns from hub_power_on() and not power-on any of the port.
> >>>>> 
> >>>>> Below is the change i suggest.
> 
> ...
> 
> >>>>> can you please confirm if you problem is related to this BUG in the
> >>>>> sequence of power-cycling the ports.
> >>>> 
> >>>> I applied that change, and it does not solve the problem on Tegra, nor
> >>>> do I see any of the messages that were changed from debug to printf.
> 
> ...
> 
> >>> seaboard which i can see has 3 controllers.
> >> 
> >> Vivek, what do I have to revert to fix this flub? I will do that now,
> >> since this discussion is stalled.
> > 
> > 0bf796f usb: hub: Parallelize power-cycling of root-hub ports
> > 020bbcb usb: hub: Power-cycle on root-hub ports
> > 
> > Above two patches are the one which changed the hub_power_on()
> > functionality. If Stephen can confirm that reverting these patches
> > really solves the problem on Tegra,
> > we can revert them.
> 
> Yes, I have been reverting those two commits locally for a while, and it
> solves the problem for me.

Reverted, please test u-boot-usb/master .

Best regards,
Marek Vasut