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

[Stephen Warren]

On 07/08/2013 12:25 PM, Marek Vasut wrote:
> Dear Stephen Warren,
> 
>> On 07/08/2013 11:03 AM, Marek Vasut wrote:
>>> 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.
>>
>> ...
>>
>>>>>> 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 .
>>
>> Well, it works, but it turns out the reverts aren't needed. Simon Glass
>> already found the problem, and fixed it with:
>>
>> ed10e66 usb: Correct CLEAR_FEATURE code in ehci-hcd
>>
>> Sorry for not noticing this earlier, but since there hadn't been any
>> news in this thread, and there weren't any relevant changes to the
>> power-cycling code affected by the problematic patches, it didn't occur
>> to me that the problem may have already been fixed elsewhere, so I
>> didn't ever retest the issue with a newer commit than that one where I
>> originally found the problem:-(
> 
> OK, I dropped the reverts, retest again please.

I had already tested the commit in your tree right before the reverts
(a36466c50b1b3614c3cfdae194227f7dd8e2c592); that's how I noticed that
the reverts weren't necessary, since I'd expected that commit to fail
but it didn't.