[Letux-kernel] weird problem with pwm_bl on omap3

H. Nikolaus Schaller hns at goldelico.com
Wed May 30 08:24:09 CEST 2018


> Am 30.05.2018 um 08:08 schrieb Andreas Kemnade <andreas at kemnade.info>:
> On Tue, 29 May 2018 22:03:52 +0200
> "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
>> Ah,
>> more info below
>>> Am 29.05.2018 um 21:55 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
>>> Hi,
>>>>> GTA04A5 that a GTA04A4.
>>>> Reproducible with letux-4.17-rc5  
>>> Good (even if bad :)
>>>> not reproducible with  mainline 4.17-rc7 + letux-4.17-rc5 dtb  
>> Here is an excerpt from by bisect script which makes it appear if I
>> pick this minimal set of letux branches/commits on top of mainline 4.16..4.17:
>> 			picklatest work/letux-base/dt-gta04-common || return
>> 			picklatest work/letux-base/arm_defconfig || return
>> 			picklatest work/letux-base/Letux || return
>> 			picklatest work/letux-base/compile-fixes || return
>> 			picklatest work/letux-base/dt-gta04 || return
>> 			pick 18ee03dc6f6b || return	# full serdev patchset may end in merge conflict
>> 			picklatest work/letux-base/dt-gta04a5 || return
>> 			picklatest work/letux-base/marek/generic-adc-battery || return	# because we include some .dtsi
>> 			picklatest work/letux-base/hacks || return
>> 			picklatest work/letux-base/ubi-fs || return
>> So if I did not make a mistake it should be in one of these branches.
> hmm, your latest backtrace shows letux-specific modules, so maybe you are still using them from older compiles?

Ah, that could indeed happen. Debugging the debugging tools is also needed :)

Have to check if rsync to the SD card does not delete them.
And as long as the Linux kernel version matches, depmod and modprobe would still locate them on the SD.

> I delete CONFIG_LOCALVERSION when compiling mainline.

Anyways I did try to revert

4e3996d3a048 drm/omap: work-around for omap3 display enable
5518e5b3554b drivers: omap: dmtimer: this hack solves L3 custom errors

with no change.

Now I have stripped the above list down even further (we just need 867e994fbd63 dt-bindings: power: Add battery types
from the g-a-b branch to get the DT compiled).

Then I can check the "stale kernel module" topic.

But it should not harm too much since I did not see the strcmp(NULL) with 4.16.0 but with 4.17-rc1.
which would mean that the diff must be in the recompiled modules or uImage.


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