> > > 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
> > > USB2
> >
> > 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 the 4
> > > 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
> > cpus online.
> >
> /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 detect
> > > 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 it's
> > 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
> > anyone's guess.
> >
> > > 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
> > grub options?
> > > Thanks in advance for your comments and feedback!
> >
> > See above.
>
> 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 fast.
man 5 dracut.conf
_______________________________________________
arm mailing list -- arm@lists.fedoraproject.org
To unsubscribe send an email to arm-leave@lists.fedoraproject.org
Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: https://lists.fedoraproject.org/archives/list/arm@lists.fedoraproject.org/message/LD6IAHKKSXIE2IVW6NNCEICD2KZLEV6Q/
No comments:
Post a Comment