usb_drv error -92 for RPi | Genode 18.05 with Fiasco.OC 79

[Tomasz Gajewski]

It is a very old thread but it seems I found root cause of this problem
and I think that it can be important to inform about my findings. I
added comments below.


Alexander Weidinger <alexander.weidinger at tum.de> writes:

> unfortunately I'm still struggling with the USB driver (and therefore
> Network) of the Raspberry Pi 2 (and 3).

I've been fighting with exactly this problem for past month.

> As one can see, for the RPi 3 sometimes! the USB driver works and
> therefore I assume the same should be possible for the RPi 2.
> At least they they do share the same USB/Network-Chip (LAN9514).

I did not check networking yet but eliminated -92 errors for keyboard
and mouse.

> I checked the memory map and adapted the base addresses accordingly,
> the interrupts seem to have not changed between RPi 1 and RPi 2
> (apart from the multicore aspect).
>
> Even some USB urbs are sent until the error -92 appears.

They seemed to be sent but during those "sends" device was not properly
informed about memory address for use for dma.

On rpi3 (and others) there is a difference between bus addresses and
physical addresses. In [1] I made a "brutal" fix working for
rpi3. It is definitely not the final one as it is not just for rpi.

> I currently have no idea where else to look and therefore I would be
> helpful for any hints I can get, regarding how I should continue to
> solve the problem I have with the USB driver.

> Is the usb_otg/usb_dwc driver just not compatible with the Raspberry Pi
> 2 and I should look at the current driver situation in the Linux Kernel?
> As far as I know usb_otg/usb_dwc was used in the early time for the
> Raspberry Pi 2 until it got replaced by dwc2?
> Anyone has an idea if/what big difference there is between the driver
> versions dwc and dwc2?
> Would it make sense to look at the new driver and port it to Genode?

During my attempts I ported this new driver and it did not help so
probably fixing dma can help on previous versions of the driver too.

> Thanks in advance! Any help is appreciated!

Alexander, I don't know if you are still interested in this but if you
check if my findings help I would definitely like to know about this.

Regards
Tomasz Gajewski

[1] https://github.com/tomga/genode/commit/61abaa60eb18c8cd89a030b522f54c943d438b50

> Regards,
> Alexander
>
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-- 
Tomasz Gajewski