[U-Boot] Issue with USB mass storage (thumb drives)

[Hannes Schmelzer]

On 04.02.2016 12:28, Marek Vasut wrote:
> On Thursday, February 04, 2016 at 09:21:08 AM, Schrempf Frieder wrote:
>> On 03.02.2016 20:16, Sergei Temerkhanov wrote:
>>> On Wed, Feb 3, 2016 at 8:40 AM, Marek Vasut <marex at denx.de> wrote:
>>>> On Wednesday, February 03, 2016 at 12:49:20 PM, Schrempf Frieder wrote:
>>>>> On 03.02.2016 12:12, Marek Vasut wrote:
>>>>>> On Wednesday, February 03, 2016 at 11:15:00 AM, Schrempf Frieder wrote:
>>>>>>> On 03.02.2016 10:55, Fabio Estevam wrote:
>>>>>>>> On Wed, Feb 3, 2016 at 7:40 AM, Marek Vasut <marex at denx.de> wrote:
>>>>>>>>> In that case, debug time.
>>>>>>>>>
>>>>>>>>> Usual problems are bad routing of the tracks on the board , so try
>>>>>>>>> with USB 1.1 hub and if that works, that's your problem.
>>>>>>>> Another suggestion would be to try the 100MB transfer in Linux and
>>>>>>>> see if this works or not.
>>>>>>>>
>>>>>>>> That would help us to narrow down whether this is a hardware or
>>>>>>>> software problem.
>>> Another thing to try may be limiting the value of USB_MAX_XFER_BLK in
>>> common/usb_storage.c
>> This was a really helpful hint! Thank you Sergei!
>>
>> I just tried to limit USB_MAX_XFER_BLK to 1/8 of the original value
>> (65535 -> 8191) and this time the transfer works without timeouts.
>>
>> As we have a customer who needs this working as soon as possible my
>> question now is how to properly solve this.
>> Should I generally limit USB_MAX_XFER_BLK in my u-boot to avoid these
>> errors? Which value to choose?
> Nice! Can you share which sticks are those, ideally brand/type and USB IDs ?
Hi,
that tip works also on my ZYNQ board.

There is some comment around this 'magic-define':

/*
  * The U-Boot EHCI driver can handle any transfer length as long as 
there is
  * enough free heap space left, but the SCSI READ(10) and WRITE(10) 
commands are
  * limited to 65535 blocks.
  */

Can i assume that 16MiB free heap space is enough if i want read a 16MiB 
file ?

> Best regards,
> Marek Vasut
best regards,
Hannes