Re: omap4 ehci sporadic resume issue

[Roger Quadros <rogerq@ti.com>]

On 06/28/2013 07:47 PM, Michael Trimarchi wrote:
> Hi
> 
> On Fri, Jun 28, 2013 at 02:46:11PM +0300, Roger Quadros wrote:
>> On 06/28/2013 02:33 PM, Michael Trimarchi wrote:
>>> Hi Roger
>>>
>>> On Thu, Jun 27, 2013 at 11:07:11PM +0300, Ruslan Bilovol wrote:
>>>> On Thu, Jun 27, 2013 at 10:24 PM, Michael Trimarchi
>>>> <michael@amarulasolutions.com> wrote:
>>
>>>> Do you have locks around this software workaround?
>>>> The patch I did against 3.4 linux kernel may be helpful for
>>>> you in such case: http://review.omapzoom.org/28515
>>>> Another patch extends this WA for all OMAP4 SoCs:
>>>> http://review.omapzoom.org/31108
>>>
>>> I'm testing using pm_test and stop to core (5ms and not 5 seconds) (usb suspend cycle are done correctly) so
>>> the problem could be:
>>>
>>> 1) SAR usb context restore. I have applied the SAR workaround but the core doesn't go in full retantion
>>> could be it a problem?
>>
>> If core doesn't go in to OFF then SAR will not come into play. Are you still affected by the
>> issue if OFF mode is disabled? If yes then it probably is not related to SAR.
>>
>>>
>>> 2) idle status of ulpis pins?
>>
>> Yes this can be possible.
>>
>> When you said earlier that the problem doesn't happen when one of the ULPIs is used
>> did you try both of them individually. e.g. case 1: port 1 only enabled,
>> case 2: port 2 only enabled.
>>
>> Did it work in both the cases?
> 
> Yes, so I don't think could be a problem of ulpi pins and why this happen
> on both at the same time? Seems more connected to somenthing else.
> 

Right. Seems to be related to two things. OFF Mode and 2 ports being used simultaneously.

I'm not sure how to go about fixing this. How important is OFF Mode for your application.
Can you keep it always disabled?

cheers,
-roger