[U-Boot] [PATCH RESEND] ARM: OMAP3: USB: Fix the EHCI ULPI PHY reset issue

[Igor Grinberg <grinberg@compulab.co.il>]

On 05/04/12 12:06, Russ Dill wrote:
> On Thu, May 3, 2012 at 11:03 PM, Igor Grinberg <grinberg@compulab.co.il> wrote:
>> Hi Russ,
>>
>> On 05/03/12 22:08, Russ Dill wrote:
>>> On Wed, May 2, 2012 at 3:38 AM, Raja, Govindraj <govindraj.raja@ti.com> wrote:
>>>> On Wed, May 2, 2012 at 2:17 PM, Russ Dill <Russ.Dill@ti.com> wrote:
>>>>> On Mon, Mar 19, 2012 at 6:34 AM, Raja, Govindraj <govindraj.raja@ti.com> wrote:
>>>>>> On Mon, Mar 19, 2012 at 12:12 PM, Keshava Munegowda
>>>>>> <keshava_mgowda@ti.com> wrote:
>>>>>>> From: Keshava Munegowda <Keshava_mgowda@ti.com>
>>>>>>>
>>>>>>> It is observed that the echi ports of 3430 sdp board
>>>>>>> are not working due to the random timing of programming
>>>>>>> the associated GPIOs of the ULPI PHYs of the EHCI for reset.
>>>>>>> If the PHYs are reset at during usbhs core driver, host ports will
>>>>>>> not work because EHCI driver is loaded after the resetting PHYs.
>>>>>>> The PHYs should be in reset state while initializing the EHCI
>>>>>>> controller.
>>>>>>> The code which does the GPIO pins associated with the PHYs
>>>>>>> are programmed to reset is moved from the USB host core driver
>>>>>>> to EHCI driver.
>>>>>>
>>>>>> I tested on beagle xm where gpio nreset is requested from
>>>>>> board file.
>>>>>> (Basic enumertaion after gpio nreset seems to work fine,
>>>>>> Hub and smsc lan chip get detected afetr boot up)
>>>>>>
>>>>>
>>>>> What base did you test this on top of? my xM is failing USB-wise when
>>>>> I apply this on v3.3.3 (with the UART mux fix patch) and where it is
>>>>> applied within master (3.4-rc4, again, with the UART mux fix patch).
>>>>> Additionally, reverting this patch from 3.4-rc5 causes rc5 to work
>>>>> properly.
>>>>>
>>>>
>>>> Works for me be on 3.4-rc5 Beagle-XM even without reverting the patch
>>>>
>>>> Logs as in here [1].
>>>>
>>>> --
>>>> Thanks,
>>>> Govindraj.R
>>>>
>>>> [1]:
>>>> http://pastebin.pandaboard.org/index.php/view/20343533
>>>
>>> I've tracked down the difference. I'm loading my uEnv.txt and uImage
>>> in u-boot from the network which means initializing USB. You are
>>> loading straight from MMC. If I switch to loading straight from MMC
>>> everything works.
>>>
>>> Can everyone do a 'usb start' in u-boot before booting and re-test?
>>> I'm pretty sure this is a regression, but the bug could be a strange
>>> u-boot/kernel interaction.
>>
>> Probably, kernel code does not reinitialize EHCI correctly if it was already enabled?
>> Can you try the below sequence:
>> usb start
>> usb stop
>> boot Linux
> 
> That doesn't work. Rebooting does work though.

This means that U-Boot's usb stop command is also not clean enough...
So we have two problems here, one is related to kernel USB initialization
and the second to U-Boot usb stop command...

-- 
Regards,
Igor.