[U-Boot] usb: Fail to get descriptor for USB 2.0 device

[Marek Vasut]

On 05/24/2018 06:23 PM, DATACOM - Paulo.Zaneti wrote:
> 
> 
> On 23/05/2018 20:40, Bin Meng wrote:
>> Hi,
>>
>> On Thu, May 24, 2018 at 4:51 AM, DATACOM - Paulo.Zaneti
>> <paulo.zaneti at datacom.com.br> wrote:
>>>
>>> On 23/05/2018 15:00, Marek Vasut wrote:
>>>> On 05/23/2018 07:52 PM, DATACOM - Paulo.Zaneti wrote:
>>>>>
>>>>> On 23/05/2018 14:43, Marek Vasut wrote:
>>>>>> On 05/23/2018 07:37 PM, DATACOM - Paulo.Zaneti wrote:
>>>>>>> On 23/05/2018 14:03, Marek Vasut wrote:
>>>>>>>> On 05/23/2018 07:00 PM, DATACOM - Paulo.Zaneti wrote:
>>>>>>>>> Hi,
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>>> When trying to migrate a board from u-boot version 2016.09 to
>>>>>>>>> version
>>>>>>>>> 2018.03, I found a problem with a USB 2.0 device which used to
>>>>>>>>> work
>>>>>>>>> on
>>>>>>>>> version 2016.09.
>>>>>>>> Does it still happen in u-boot/master ?
>>>>>>> Yes, it still happens.
>>>>>>>
>>>>>>> I just tested it with the following commit:
>>>>>>> dca268a .travis.yml: Further optimizations
>>>>>>>>> In u-boot version 2016.09 the device appears like this:
>>>>>>>>>
>>>>>>>>> 2: Mass Storage,  USB Revision 2.0
>>>>>>>>>      - SanDisk Cruzer Blade 200443243002FB509E64
>>>>>> Let me guess, is this a DWC2-based host ? You didn't mention which
>>>>>> SoC
>>>>>> or USB controller it is.
>>>>>>
>>>>>> Cfr https://lists.denx.de/pipermail/u-boot/2016-January/240090.html ,
>>>>>> DWC2 has problems with those sandisk sticks.
>>>>> No, it is a NXP T1024 SoC.
>>>>> Do you think it may be a problem with the SoC or NXP USB host driver ?
>>>>>
>>>> So that's chipidea ? That one should be reasonably sane.
>>> I don't think so. It uses following drivers:
>>>    drivers/usb/host/ehci-fsl.c
>>>    drivers/usb/host/ehci-hcd.c
>>>
>>>> Submit the patch you had in mind and let's see what happens.
>>> I just noticed that this stick needs more time after the
>>> usb_set_address()
>>> call.
>>> I increased the mdelay(10) to mdelay(20) and the "usb start" command
>>> worked.
>>> But the problem is that I am still not convinced that this should be the
>>> solution.
>>>
>> Agreed. Can you bisect to see which commit broke your stick?
> Yes. The commit which broke my stick is:
> 
> commit c008faa77358bb5b313696dd1d5bb8afa03a6ca2
> Author: Bin Meng <bmeng.cn at gmail.com>
> Date:   Mon Sep 18 06:40:42 2017 -0700
> 
>     usb: Only get 64 bytes device descriptor for full speed devices
> 
> 
> My first guess was that this commit should be adapted to
> "get_descriptor_len()" for USB_SPEED_HIGH too.
> 
> But then, I realized that I can bypass this problem by increasing the
> mdelay() after usb_set_address() from 10 to 20 msec.
> 
> So, I think commit c008faa77358bb5b313696dd1d5bb8afa03a6ca2 is not the
> offender one. It probably uncovered another problem with this stick.

That particular lineup of sandisk sticks is trash, I have a few of those
here for testing too.

> I will try to get a better understanding before submitting a patch.

Did usb_pgood_delay help ?

-- 
Best regards,
Marek Vasut