4.5.0 on sun7i-a20-olinuxino-lime2: libphy: PHY stmmac-0:ffffffff not found (regression from rc7)

[Marc Zyngier]

On Sat, 21 May 2016 17:47:05 +0200
Bert Lindner <bert at a20.net> wrote:

> Hi,
> 
> On 2016-05-20 12:36, Marc Zyngier wrote:
> > On 20/05/16 11:30, Andre Heider wrote:
> >> Hi,
> >>
> >> On Fri, May 20, 2016 at 10:14 AM, Giuseppe CAVALLARO
> >> <peppe.cavallaro at st.com> wrote:
> >>> On 5/20/2016 9:56 AM, Marc Zyngier wrote:
> >>>>
> >>>> On 20/05/16 06:44, Andre Heider wrote:
> >>>>>
> >>>>> Giuseppe, Alexandre, et al.,
> >>>>>
> >>>>> On Thu, Mar 17, 2016 at 8:52 AM, Marc Zyngier <marc.zyngier at arm.com>
> >>>>> wrote:
> >>>>>>
> >>>>>> On Thu, 17 Mar 2016 00:56:40 +0100
> >>>>>> Bert Lindner <bert at a20.net> wrote:
> >>>>>>>
> >>>>>>> On 2016-03-16 18:42, Marc Zyngier wrote:
> >>>>>>>>
> >>>>>>>> On 16/03/16 15:10, Bert Lindner wrote:
> >>>>>>>>>
> >>>>>>>>> On 2016-03-16 14:10, Andreas Färber wrote:
> >>>>>>>>>>
> >>>>>>>>>> Am 16.03.2016 um 13:09 schrieb Robin Murphy:
> >>>>>>>>>>>
> >>>>>>>>>>> On 16/03/16 11:39, Marc Zyngier wrote:
> >>>>>>>>>>>>
> >>>>>>>>>>>> On 16/03/16 11:19, Bert Lindner wrote:
> >>>>>
> >>>>> ...
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> For the board sun7i-a20-olinuxino-lime2, there seems to be a
> >>>>>>>>>>>>> problem
> >>>>>>>>>>>>> with the eth0 PHY in mainline kernel 4.5.0 that developed since
> >>>>>>>>>>>>> 4.5.0-rc7. Ethernet does not work, although eth0 is reported:
> >>>>>
> >>>>> ...
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> [    9.767125] NET: Registered protocol family 10
> >>>>>>>>>>>>> [   10.357405] libphy: PHY stmmac-0:ffffffff not found
> >>>>>>>>>>>>> [   10.362382] eth0: Could not attach to PHY
> >>>>>>>>>>>>> [   10.366557] stmmac_open: Cannot attach to PHY (error: -19)
> >>>>>
> >>>>> ...
> >>>>>>>>>>
> >>>>>>>>>> v4 fixes for 4.5 are here:
> >>>>>>>>>>
> >>>>>>>>>> https://patchwork.ozlabs.org/patch/598195/ (revert)
> >>>>>>>>>> https://patchwork.ozlabs.org/patch/598196/
> >>>>>
> >>>>> ...
> >>>>>>>>
> >>>>>>>> Good to know, thanks. Could you also give the potential fix a go (as
> >>>>>>>> mentioned by Andreas)? Just to make sure that whatever gets merged
> >>>>>>>> next
> >>>>>>>> will actually fix the issue.
> >>>>>>>
> >>>>>>>
> >>>>>>> Yes sure, it took a while because I had to travel. Confirmed, the
> >>>>>>> v4-for-4.5 fix works well for me, on sun7i-a20-olinuxino-lime2:
> >>>>>>>
> >>>>>>> root at lime2-079f:~# cat /proc/version
> >>>>>>> Linux version 4.5.0-598195-598196-v4 (root at lime2-079f) (gcc version
> >>>>>>> 4.9.1 (Ubuntu/Linaro 4.9.1-16ubuntu6) ) #1 SMP Wed Mar 16 16:44:22 UTC
> >>>>>>> 2016
> >>>>>>>
> >>>>>>> dmesg:
> >>>>>>> [    8.245273] NET: Registered protocol family 10
> >>>>>>> [    9.297406]  RX IPC Checksum Offload disabled
> >>>>>>> [    9.297460]  No MAC Management Counters available
> >>>>>>> [    9.297951] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
> >>>>>>> [   16.285658] sun7i-dwmac 1c50000.ethernet eth0: Link is Up -
> >>>>>>> 1Gbps/Full - flow control rx/tx
> >>>>>>> [   16.285798] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
> >>>>>>>
> >>>>>>> The board is connected to my laptop rather than to a switch, so that
> >>>>>>> might be where the flow control message comes from (not sure). Anyway
> >>>>>>> ethernet works.
> >>>>>>
> >>>>>>
> >>>>>> Cool, many thanks for taking the time to test and report.
> >>>>>>
> >>>>>> Hopefully Giuseppe will get this merged quickly enough in mainline, and
> >>>>>> it should then trickle into a 4.5-stable release (cc-ing stable on
> >>>>>> these patches would probably be a good idea, BTW).
> >>>>>
> >>>>>
> >>>>> stmmac is broken on at least Lime2, BananaPi and Cubieboard2 since
> >>>>> v4.5 [0], including all five stable releases :(
> >>>>
> >>>>
> >>>> All the A20 platforms are dead, actually.
> >>>>
> >>>>> The v4.5 patches quoted above are already +4 weeks old, could we
> >>>>> please get them into stable?
> >>>>
> >>>>
> >>>> For that, the maintainer would have needed to CC stable, which he
> >>>> didn't. I'd expect someone who cares to send these patches to stable.
> >>>> It'd be better if the maintainer would do it himself though.
> >>>
> >>>
> >>> sure, I can send the patches to stable (sorry if I missed to add
> >>> stable ML on CC).
> >>>
> >>> Andre, I have not clear if the train of patches actually fix the
> >>> issue or if you need my support to fix something else. In that case
> >>> I need some input for debugging (e.g. kernel log).
> >>
> >> Bert already confirmed that those two patches fixes stmmac on his
> >> Lime2, so I assume that it fixes the issue for all A20 platforms.
> >>
> >>> let me know, is it enough to re-send the patches only?
> >>
> >> Just a resend with cc:stable :)
> >
> > Not quite. Please read Documentation/stable_kernel_rules.txt, and the
> > section that concerns networking patches (and then consult
> > Documentation/networking/netdev-FAQ.txt which has all the details).
> 
> FWIW, recent 4.6-rc series and 4.6.0 have worked fine for me and the 
> lime2. Had not tried 4.5.x again.

We've already established this. This is a 4.5-specific regression (both
4.4 and 4.6 are fine). One major issue is that Debian Stretch is
currently shipping with 4.5, and upgrading to it results in a system
without networking. Should this patch make it into stable, the fix would
quickly percolate into distro kernels, and we could forget about it.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny.