From: Peter Robinson [mailto:email@example.com]
Sent: Wednesday, August 22, 2018 3:42 PM
Subject: Re: [fedora-arm] F28 on odroid XU4
> First of all I would like to thank all contributors for figuring out
> the bits and pieces that make the F28 images bootable and functional
> on the odroid XU4.
> However, I noticed a couple of things after booting the F28 server image:
> - network interface (r8152) is connected as USB2
> - connecting USB3 devices seems to be hit or (mostly) miss, they are
> detected by the xhci driver, but usually after they are already
> connected as
What kernel are you running? Are you running the GA kernel
(4.16.something?) or have you upgraded to the latest (4.17.x) as I believe
both of those issues were fixed in updates kernels.
I noticed this with 4.16.3-301.fc28 included in the image, but there was the same
behaviour with 4.17.11-200.fc28 and rawhide 4.18.0-0.rc7.git2.1.fc29. I have to say things
indeed _do_ work with the default f28 kernels, you only notice the performance issue by
checking the output of lsusb -t, dmesg or console when plugging in a USB3 device. My guess
is there is some kind of race between the ehci/ohci and xhci modules, with the latter
being loaded too slow or too late, because I do see detection messages for both USB2 and
USB3 on the console, but usually USB2 comes first and USB3 after connection is established
as USB2. Since r8152 is USB based, this probably is linked.
> - it seems like only the 4 A7 cores are active and switching to
> A15 cores is not possible
Hmm, what does lscpu report? Also what u-boot are you using? I'm not 100%
sure here but I thought they were working, although with big.little I'm not
sure wthether they switch the whole cluster under load or just bring more
/proc/cpuinfo reports the 4 A7 cores, upon loading (load average>4) I can see
these cores up in /sys/.../cpu[0-3], but the A15 cores cpu[4-7] don't seem to become
active. Lscpu I don't know by heart, would need to check. The line " #
CONFIG_BL_SWITCHER is not set" changes this to all 8 cores up all the time (exynos
HMP). Again, the system works, but with reduced performance.
The u-boot is the one for odroid-xu3 in the fedora 28 image, cat of .bin and .dtb. Not
sure if the cat is required.
> Since I noticed the Hardkernel Ubuntu image does correctly
> USB3, the issue could not be purely related to hardware design or bus
> power, so I decided to recompile (then) F28 kernel 4.17.11-200 with
> some alternative config settings, compiling in lots of USB related
> modules. In the end I got to the point where USB3 devices and the
> Ethernet chip indeed are detected as USB3, some more fiddling also
enabled all 8 cores simultaneously.
> Attached you find the kernel-local used to modify the config, which
> still can use some cleaning up.
I would need a diff against the fedora config because I don't have the time to
work out what's changed but a lot of stuff is built in by the look of it and
that's not going to happen in the upstream kernel, it's also strange that
needed since others have reported it works fine, it of course could be a
regression but the above changes work around a regression not fix it. The
Hardkernel group have never been particularly upstream friendly so it's
> One point now remains, these adjustments require recompiling the
> kernel each time an update is available, thus breaking an easy update
> path. Would there be a way to achieve a similar result using initramfs and
> Thanks in advance for your comments and feedback!
Everything works, but some bits and pieces seem sub-optimal. Could anyone else check the
output of `lsusb -t` on an odroid XU4 with stock fedora 28/29 kernel? I'm mostly
interested in the USB stuff, if that is sorted out, I can easily evaluate cpu power. Maybe
just A7 already does the trick.
The main difference between both kernel configs is built in vs module for USB related
stuff, so this makes me wonder about modifying initramfs and/or grub instead of
recompiling. Any suggestion to this end would be appreciated and can be tested quite