[U-Boot] [[PATCH v2 5/6] USB: ehci: Add a weak function for resetting devices

[Dan Murphy <dmurphy@ti.com>]

Roger
On 07/11/2013 09:23 AM, Roger Quadros wrote:
> Hi Marek,
>
> On 07/11/2013 03:35 PM, Marek Vasut wrote:
>> Dear Roger Quadros,
>>
>>> On 07/11/2013 02:16 AM, Dan Murphy wrote:
>>>> On 07/10/2013 05:20 PM, Marek Vasut wrote:
>>>>> Dear Dan Murphy,
>>>>>
>>>>>> Add a __weak function that can be overridden to reset devices
>>>>>> attached to an ehci devices after the FEAT_POWER has been submitted
>>>>>>
>>>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>>>> ---
>>>>>>
>>>>>>  drivers/usb/host/ehci-hcd.c |    7 +++++++
>>>>>>  1 file changed, 7 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
>>>>>> index 706cf0c..fdd3994 100644
>>>>>> --- a/drivers/usb/host/ehci-hcd.c
>>>>>> +++ b/drivers/usb/host/ehci-hcd.c
>>>>>> @@ -616,6 +616,11 @@ __weak uint32_t *ehci_get_portsc_register(struct
>>>>>> ehci_hcor *hcor, int port) return (uint32_t *)&hcor->or_portsc[port];
>>>>>>
>>>>>>  }
>>>>>>
>>>>>> +__weak void ehci_reset_attached_devices(int port)
>>>>>> +{
>>>>>> +	return;
>>>>>> +}
>>> Does this function need to be ehci specific? Other USB controllers might
>>> also need such a function.
>> You'd need to implement this for each of the xHCIs
> OK.
I can move the API to the usb-hub to call this after the FEAT_POWER is completed
>>>>>> +
>>>>> Can the reset not happen elsewhere?
>>>> I have tried to move this around and keep this out of this file
>>>> completely but nothing else seems to work.
>>>>
>>>> For port 2 where the USB3530 is we don't have the issue the 3530
>>>> enumerates properly.
>>>>
>>>> I did not see any information in the data sheet eluding to a timing
>>>> issue.
>>> This is the information I had received earlier from SMSC about USB3503A hub
This has nothing to do with the 3503A this is the LAN9730.  The 3503 works just fine
without the additional reset.
>>>
>>> "You need the host up and running, and ready to go, THEN negate RESET_N. 
>>> That is probably 95% of the issues."
>>>
>>> Please make sure the following sequence is done.
>>>
>>> - power up hub (RESET is active at this point).
>>> - start USB controller
>>> - wait a few ms
>>> - release hub RESET.
>>>
>>> giving a quick look at the u-boot code it seems you need to release the hub
>>> reset after usb_lowlevel_init() _OR_ usb_init() returns.
>> Then it would also work in usb_lowlevel_init() ?
> It should as long as we place the "release reset" after EHCI controller
> has started. Maybe safer to put it in the end of usb_lowlevel_init().
>
> cheers,
> -roger
I moved the reset to the usb_lowlevel_init and it did not work.
I tried holding the 9730 in reset until after ehci hcd init is complete and pulled it out of
reset once the hcd is initialized but still no enumeration.

Dan

-- 
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Dan Murphy