[U-Boot] Regression in fastboot on X15 due to CDCE913 enabling

[Vignesh Raghavendra]

Hi Sam,

On 24-Oct-19 7:16 PM, Sam Protsenko wrote:
> Putting Vignesh to "To:".
> 
> Hi Vignesh,
> 
> Please address Tero's comments below (I've marked with ^^^). Thanks.
> 
> On Thu, Oct 24, 2019 at 3:54 PM Tero Kristo <t-kristo at ti.com> wrote:
>>
>> On 24/10/2019 13:32, Sam Protsenko wrote:
>>> Hi Tero,
>>>
>>> On Thu, Oct 24, 2019 at 10:32 AM Tero Kristo <t-kristo at ti.com> wrote:
>>>>
>>>> On 23/10/2019 17:20, Sam Protsenko wrote:
>>>>> + fixed U-Boot mailing list address
>>>>>
>>>>> On Wed, Oct 23, 2019 at 3:13 PM Sam Protsenko
>>>>> <semen.protsenko at linaro.org> wrote:
>>>>>>
>>>>>> Hi Tero,
>>>>>>
>>>>>> This patch was merged in U-Boot/master recently:
>>>>>>
>>>>>>       e8e683d33b0c ("board: ti: am57xx-idk: Configure the CDCE913 clock
>>>>>> synthesizer")
>>>>>>
>>>>>> Unfortunately it leads to a regression in fastboot code on BeagleBoard
>>>>>> X15. Basically fastboot stops to work, with a message like this:
>>>>>>
>>>>>>       => fastboot 1
>>>>>>       No USB device found
>>>>>>       USB init failed: -19
>>>>>>
>>>>>> I haven't investigated that as I'm busy with Android boot flow patch
>>>>>> series at the moment (trying to merge it before merge window closes).
>>>>>> Can you please investigate what is the cause and how to fix it?
>>>>>>
>>>>>> Thanks!
>>>>
>>>> This seems to be caused by usb dwc3 init failing to get clks, if
>>>> CONFIG_CLK is enabled. We appear to have the attached patch which fixes
>>>> it in TI internal u-boot tree; it fixes the issue with latest u-boot also.
>>>>
>>>> Should this be picked for upstream also? (CC: Vignesh)
> 

Yes, this patch is applicable upstream as well. I did not get time to
post this series to upstream list.

> ^^^
> 
>>>>
>>>
>>> I can confirm that that patch helps. If it's a proper fix, can you
>>> please send it here? Also, I guess it would be nice to have next tags
>>> specified: Fixes:, Reported-by:.
>>>
>>> Thanks!
>>
>> Vignesh, any comments as you are the author of that patch? The
>> background on it is somewhat unclear to me.
>>
> 

In case of AM57xx, USB clocks are enabled by board files. Therefore clk
and reset APIs may return -ENOENT as nodes may be absent in the DT.
Since clks and resets are optional, -ENOENT needs to be ignored as well.


> ^^^
> 
>> -Tero
>> --
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