[U-Boot] Bisected broken Ethernet support on ODROID-X (Exynos4412 board)

Thu Oct 22 13:20:38 CEST 2015

Hi Siarhei,

> On Wed, 21 Oct 2015 10:06:09 +0200
> Lukasz Majewski <l.majewski at samsung.com> wrote:
> 
> > Hi Siarhei,
> > 
> > > On Tue, 20 Oct 2015 09:15:07 -0600
> > > Simon Glass <sjg at chromium.org> wrote:
> > > 
> > > > Hi,
> > > > 
> > > > On 20 October 2015 at 08:13, Siarhei Siamashka
> > > > <siarhei.siamashka at gmail.com> wrote:
> > > > > Hello,
> > > > >
> > > > > Ethernet support does not work anymore when using the current
> > > > > U-Boot (version v2014.10) on the ODROID-X board. Bisecting
> > > > > shows that this happened starting from commit
> > > > > 874dde80169e0a0c00020e2e0bbcd380c61097e3 ("dm: usb: exynos:
> > > > > Use driver model for USB"):
> > > > > http://git.denx.de/?p=u-boot.git;a=commitdiff;h=874dde80169e0a0c00020e2e0bbcd380c61097e3
> > > > >
> > > > > Below are the logs from the serial console.
> > > > >
> > > > > === works properly ==
> > > > >
> > > > > U-Boot 2015.04-00271-g52e6935-dirty (Oct 20 2015 - 16:38:09)
> > > > >
> > > > > CPU:    Exynos4412 at 1000MHz
> > > > > Model: Odroid based on Exynos4412
> > > > > DRAM:  1 GiB
> > > > > Board PMIC init
> > > > > MMC:   SAMSUNG SDHCI: 0, EXYNOS DWMMC: 1
> > > > > Net:   No ethernet found.
> > > > > Hit any key to stop autoboot:  0
> > > > > reading boot.scr
> > > > > 129 bytes read in 11 ms (10.7 KiB/s)
> > > > > ## Executing script at 40408000
> > > > > starting USB...
> > > > > USB0:   USB EHCI 1.00
> > > > > scanning bus 0 for devices... 4 USB Device(s) found
> > > > >        scanning usb for storage devices... 0 Storage Device(s)
> > > > > found scanning usb for ethernet devices... 1 Ethernet
> > > > > Device(s) found
> > > > >
> > > > > === fails ==
> > > > >
> > > > > U-Boot 2015.04-00273-g78ab40b-dirty (Oct 20 2015 - 16:41:11)
> > > > >
> > > > > CPU:    Exynos4412 at 1000MHz
> > > > > Model: Odroid based on Exynos4412
> > > > > DRAM:  1 GiB
> > > > > Board PMIC init
> > > > > MMC:   SAMSUNG SDHCI: 0, EXYNOS DWMMC: 1
> > > > > Net:   No ethernet found.
> > > > > Hit any key to stop autoboot:  0
> > > > > reading boot.scr
> > > > > 129 bytes read in 12 ms (9.8 KiB/s)
> > > > > ## Executing script at 40408000
> > > > > starting USB...
> > > > > USB-1:   USB EHCI 1.00
> > > > > scanning bus 0 for devices... 1 USB Device(s) found
> > > > >        scanning usb for ethernet devices... 0 Ethernet
> > > > > Device(s) found
> > > > >
> > > > > ===
> > > > >
> > > > > As a test, reverting f56da290b8df14a058b43735494dbbb0f8521a89
> > > > > ("Drop the code that doesn't use driver model for USB.") and
> > > > > disabling CONFIG_DM_USB in odroid_defconfig makes it work
> > > > > again.
> > > > 
> > > > Does this problem happen on the XU3?
> > > 
> > 
> > Yes, It does. 
> > 
> > I'm struggling to fix this issue for a few days now.
> >
> > What is interesting though, you can run ethernet by calling:
> > "usb start" and afterwards "usb reset".
> 
> That's a very interesting observation indeed. 
>  
> > > I don't have XU3. My only board is ODROID-X (the same as
> > > ODROID-X2, but with slower CPU clock speed and less RAM).
> > > 
> > > > Are you able to debug this?
> > > 
> > > I'm not sure if I can really spend much time on it. Debugging this
> > > issue would require comparing the old exynos usb code and the new
> > > dm code to see where exactly they differ. For example, the new
> > > 'ehci_usb_probe()' function does not call 'board_usb_init()' while
> > > the old 'ehci_hcd_init()' function did:
> > >     http://git.denx.de/?p=u-boot.git;a=blob;f=drivers/usb/host/ehci-exynos.c;h=86cf6312febc30b7e142146c3b4763a6a871d5a6;hb=02e4d3fbc54b345883d9bead4f2a911d0f0f59b1#l329
> > > And just calling 'board_usb_init()' on ODROID-X is still not
> > > enough
> > 
> > I will say even more - it seems like the issue is not related to any
> > "basic" initialization (i.e. the lack of calling
> > ehci_usb_probe|reset_usb_phy) called just before calling "usb
> > start".
> > 
> > > to get this problem resolved for the CONFIG_DM_USB=y
> > > configuration, so there must be something else.
> > 
> > +1
> > 
> > > 
> > > I also don't quite like that the usb parts of the U-Boot dts files
> > > for exynos differ from the Linux dts files.
> > 
> > This is a really good questions. We have discussed it recently on
> > ELCE and there is no good solution for it.
> > 
> > We made a mistake to allow non Linux compliant bindings to slip into
> > u-boot. Now we must cope with (or fix) this mess.
> 
> OK, I see. Thanks for explaining.
> 
> But if the kernel is considered to be the primary source of dts files,
> then probably U-Boot needs to be eventually adjusted to match?

We will try to converge to linux kernel, however such process will take
some time, since it is almost impossible to change all bindings at once.

> 
> > > So far I'm satisfied that the old exynos usb code still works if
> > > its removal is reverted.
> > 
> > As I've stated above - please try "usb start" and "usb reset"
> > afterwards.
> 
> Thanks, doing "usb start" followed by "usb reset" makes the ethernet
> work on ODROID-X with the CONFIG_DM_USB=y configuration if I also
> add a missing call to the 'board_usb_init()' function. It does a bit
> of necessary setup magic for odroid:
>     http://git.denx.de/?p=u-boot.git;a=blob;f=board/samsung/odroid/odroid.c;hb=v2015.10#l467
> 
> And if there is no call to 'board_usb_init()', then the ethernet
> does not work on ODROID-X after "usb reset".
> 
> > > And debugging U-Boot was not my primary
> > > intention when fetching this old ODROID-X board from a closet.
> > > I had plans to do some other interesting tests with it :-)
> > > 
> > > If Przemyslaw Marczak (the ODROID boards maintainer) could confirm
> > > the problem on ODROID-X2 and take care of it, then this would be
> > > the best for me.
> > 
> > I'm working on this issue now.
> 
> This is a very good news. Thanks a lot! I'll be happy to test the
> fixes.
> 

Thanks,

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group