[Letux-kernel] Debugging 4.11-rc6 on GTA04

Tue Apr 11 22:00:18 CEST 2017

> Am 11.04.2017 um 21:42 schrieb Andreas Kemnade <andreas at kemnade.info>:
> 
> On Tue, 11 Apr 2017 20:28:11 +0200
> "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
> 
>> 
>>> Am 11.04.2017 um 20:22 schrieb Andreas Kemnade <andreas at kemnade.info>:
>>> 
>>> On Tue, 11 Apr 2017 20:10:52 +0200
>>> "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
>>> 
>>>> 
>>>>> Am 11.04.2017 um 19:49 schrieb Andreas Kemnade <andreas at kemnade.info>:
>>>>> 
>>>>> On Tue, 11 Apr 2017 15:36:32 +0200
>>>>> "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
>>>>> 
>>>>>> Hi Andreas,
>>>>>> 
>>>>>>> Am 11.04.2017 um 12:43 schrieb Andreas Kemnade <andreas at kemnade.info>:
>>>>>>> 
>>>>>>> On Mon, 10 Apr 2017 22:01:28 +0200
>>>>>>> "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
>>>>>>> 
>>>>>>>> 
>>>>>>>>> Am 10.04.2017 um 20:13 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
>>>>>>>>> 
>>>>>>>>> Hi,
>>>>>>>>> I have found a little time to upgrade our tree to 4.11-rc6
>>>>>>>>> and for the first time there were no kernel oops on the GTA04(A5)
>>>>>>>>> until login.
>>>>>>>>> 
>>>>>>>>> Only the LCD is broken :(
>>>>>>>>> 
>>>>>>>>> On the Pyra the same kernel works well. So it seems to be
>>>>>>>>> OMAP3 specific (maybe again some interference of the TILER
>>>>>>>>> addition, but I can easily check by merging my 4.11-rc6
>>>>>>>>> without TILER).
>>>>>>>> 
>>>>>>>> I have now built w/o TILER and for the first two boot attempts I had the
>>>>>>>> same error. But the third one succeeded. This time I got
>>>>>>> [...]
>>>>>>>> 
>>>>>>>> And the ethernet gadget was not loaded (initially). No VBUS event reported. But charger started charging.
>>>>>>>> 
>>>>>>>> After unplugging the USB cable I got:
>>>>>>>> 
>>>>>>>> root at letux:~# [  230.016326] musb-hdrc musb-hdrc.0.auto: VBUS_ERROR in b_idle (90, <VBusValid), retry #0, port1 00000100
>>>>>>>> 
>>>>>>>> And then:
>>>>>>>> 
>>>>>>>> [  237.857330] g_ether gadget: high-speed config #1: CDC Ethernet (ECM)
>>>>>>>> [  238.624481] IPv6: ADDRCONF(NETDEV_CHANGE): usb0: link becomes ready
>>>>>>>> 
>>>>>>>> Otherwise I didn't see any significant issue.
>>>>>>>> 
>>>>>>>> So it looks as if we still have two bugs: one in musb and another one in TILER/crtc.
>>>>>>>> 
>>>>>>> Sounds like problems which can be bisected on mainline. I think I will
>>>>>>> bisect this evening a bit. With musb, there is probably just another
>>>>>>> enable/disable balancing problem which must be somehow worked around in
>>>>>>> the glue layer or phy.
>>>>>> 
>>>>>> Good ideas!
>>>>>> 
>>>>>> But this gave me another idea... I have added a command line option to my
>>>>>> merge script so that it ignores the mergefile. Then I can add a handful
>>>>>> of our feature branches to be merged on top of letux-base.
>>>>>> 
>>>>>> With these ones, I could get it compiled and run on the GTA04A5 (of course missing sound,
>>>>>> inverted touch etc.):
>>>>>> 
>>>>>> ./merge -p -nmf -- work/hns/letux/rootfs work/hns/dt/gta04 work/hns/dt/gta04a5 work/hns/mtd/onenand work/marek/generic-adc-battery work/hns/misc/w2sg-serdev
>>>>>> 
>>>>>> Result is at:
>>>>>> 
>>>>>> http://git.goldelico.com/?p=gta04-kernel.git;a=shortlog;h=refs/heads/letux-4.11-rc6%2Brootfs%2Bgta04%2Bgta04a5%2Bonenand%2Bgeneric-adc-battery%2Bw2sg-serdev
>>>>>> 
>>>>>> Interestingly our feature branches are not as independent as they should
>>>>>> be... The generic adc battery is needed for some #include in the GTA04DT and
>>>>>> GTA04A5 wants to modify a bluetooth node that comes through the w2sg-serdev
>>>>>> branch.
>>>>>> 
>>>>>> Anyways, the important information is: with this minimum set of feature branches
>>>>>> I have neither problems with musb nor display. So the issue is not coming from
>>>>>> mainline...
>>>>>> 
>>>>> Well, I have just a white screen here with that. So, there is more...
>>>> 
>>>> Hm. That is unexpected... I am not 100% sure if I did a clean build.
>>>> 
>>>>> 
>>>>> AFAICR, the most important this
>>>>> missing in twl4030_charger are the things to have detection working when
>>>>> the stuff is loaded. So for mainline experiments, the idea would be to
>>>>> build musb/twl stuff not as modules. And keep our device tree.
>>>> 
>>>> Well, the strangest thing is that I have merged all the listed branches on
>>>> top of letux-base and all of them work.
>>>> 
>>>> So I am either making a systematic mistake or the real bug is outside of the
>>>> musb/twl4030 subsystem.
>>>> 
>>> I checked 4.10.0 mainline + letux-4.11-rc6 feature branch -> working
>>> display (besides of non-calibrated touchscreen, could log in via usb
> 
> oops, incorrect information here:
> 4.10.0 mainline combined with dtb from letux-4.11-rc6 works.

Ah, I see. There were not many changes in dtb but most in infrastructure
so that result seems to be quite likely.

> 
>>> 
>>> mainline 4.11-rc6 funny moving stripes on the display, no usb.
>> 
>> Ah, you mean mainline. I haven't tested that but letux-base which has some
>> old (but probably important) patches we have not yet extracted into separate
>> feature branches. Recently I worked out a strategy but it is still a lot
>> of manual work (resolve rebase conflicts).
>> 
>>> 
>>>> I think I will have to bisect the mergefile until I find the problematic
>>>> feature branch...
>>> 
>>> I still blame mainline. But I do not like these bugs which happen only
>>> sometimes.
>> 
>> letux-base plus some minimal feature branches for the GTA04A5 work,
>> but the full set doesn't. So it is something in the set of our feature branches.
>> 
> I have tested your last branch and it has still display problems here!
> And there should be no reason why 4.11-rc6 mainline should work less
> than 4.10.0 mainline.
> At the moment I am bisecting mainline, 9 steps to go.

Ok!

Maybe mainline has another bug. Or our latest patches trigger that in 4.11
but not in 4.10.

I am still bisecting the feature branches. Is a slow process because my compiler
isn't the fastest one (although it runs on a SSD). And then coyping to the
SD card and booting and analysing is quite some work. Maybe also 9 steps :)

BR,
Nikolaus

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