Re: [BUG] Error applying setting, reverse things back on lot of devices

[Michał Mirosław]

On Wed, Nov 04, 2020 at 11:28:45AM +0100, Ahmad Fatoum wrote:
> Hello,
> 
> On 11/2/20 9:27 PM, Michał Mirosław wrote:
> > On Mon, Nov 02, 2020 at 01:48:54PM +0100, Ahmad Fatoum wrote:
> >> Hello Michał,
> >>
> >> CC += linux-stm32
> >>
> >> On 10/24/20 1:53 PM, Michał Mirosław wrote:
> >>> On Fri, Oct 23, 2020 at 10:39:43PM +0200, Corentin Labbe wrote:
> >>>> On Fri, Oct 23, 2020 at 03:42:01PM +0200, Corentin Labbe wrote:
> >>>>> On Wed, Oct 21, 2020 at 08:31:49PM +0200, Corentin Labbe wrote:
> >>>>> I have just saw thoses 3 lines which are probably the real problem.
> >>>>> I have started a new bisect with this error, but it is hitting the same "crash range" the first one.
> >>>>>
> >>>>
> >>>> I have bisected the problem to commit aea6cb99703e17019e025aa71643b4d3e0a24413 ("regulator: resolve supply after creating regulator")
> >>>> Reverting this fix my problem.
> >>
> >> The change broke boot on all the STM32MP1 boards, because the STPMIC driver
> >> has a vref_ddr regulator, which does not have a dedicated supply, but without
> >> a vref_ddr-supply property the system now no longer boots.
> > [...]
> > 
> > Can you catch debug logs for the bootup in question? I'm not sure what's
> > the failure mode in your case. I guess this is not a bypassed regulator?
> 
> Boot up with v5.10-rc2 + your cf1ad559a2 ("regulator: defer probe when trying
> to get voltage from unresolved supply") hangs:
> 
> [    1.151489] stm32f7-i2c 40015000.i2c: STM32F7 I2C-0 bus adapter
> [    1.180698] stpmic1 1-0033: PMIC Chip Version: 0x10
> [    1.189526] vddcore: supplied by regulator-dummy
> [    1.195633] vdd_ddr: supplied by regulator-dummy
> [    1.201672] vdd: supplied by regulator-dummy
> [    1.207452] v3v3: supplied by 5V2
> [    1.211997] v1v8_audio: supplied by v3v3
> [    1.218036] v3v3_hdmi: supplied by 5V2
> [    1.223626] vtt_ddr: supplied by regulator-dummy
> [    1.227107] vdd_usb: supplied by regulator-dummy
> [    1.234532] vdda: supplied by 5V2
> [    1.239497] v1v2_hdmi: supplied by v3v3
[...]

Can you try with the patches I just sent and with debug logs enabled?

The first one just plugs a memory leak, but if there is some state
changed/saved in the rdev->constraints (can't find that code, though),
this might prevent it from being overwritten.

The second patch will just tell us if you hit the early resolve case.

Best Regards,
Michał Mirosław