Hi Marek,

* Marek Szyprowski <m.szyprowski@samsung.com> [2019-03-11 12:11]:
>Hi Jochen,
>
>On 2019-02-08 20:35, Jochen Sprickerhof wrote:
>> Hi Marek,
>>
>> * Marek Szyprowski <m.szyprowski@samsung.com> [2019-02-08 13:36]:
>>>>>> On 21/01/19 16:02, Jochen Sprickerhof wrote:
>>>>> [..]
>>>>>>> I'm not sure why this it only works with the driver compiled into
>>>>>>> the
>>>>>>> kernel nor why it needs a hard reset or why it was the line was
>>>>>>> dropped
>>>>>>> when the patch was accepted. Would be great to get some feedback
>>>>>>> of the
>>>>>>> authors.
>>>>>> When XHCI driver is compiled into the kernel are the relevant PHY
>>>>>> drivers
>>>>>> compiled in as well?
>>>>> Only CONFIG_USB_PHY=y (I took the config from the
>>>>> linux-image-4.19.0-1-armmp_4.19.13-1_armhf.deb Debian package as a
>>>>> basis where this is the default).
>>>
>>> I confirm that on Odroid XU4 USB 3.0 works only when all related drivers
>>> (dwc3, xhci and exynos5 drd phy) are compiled into the kernel. If they
>>> are compiled as modules, USB 3.0 calibration doesn't work. The mentioned
>>> patch doesn't fix anything.
>>
>> I've just tried Linux v5.0-rc5 with the Debian config and
>> USB_XHCI_PLATFORM=y and it works, thanks!
>>
>> Is there a way to make it work with xhci compiled as a module, so it
>> would work in Debian out of the box?
>
>One more comment - 5000M mode will also work with everything compiled as
>modules (dwc3, exynos5 drd phy and xhci-plat) too. Just make sure that
>xhci-plat is loaded before dwc3. This would require some manual
>configuration, because autoloading will load xhci-plat after dwc3 probe
>and switch to host mode.

Thanks so much for the hint, this made it working :). I opened a bug 
with Debian:

https://bugs.debian.org/925167

Cheers Jochen