Re: [RFC 0/3] acpipcihp: fix kernel crash on 2nd resume

[Woody Suwalski]

Woody Suwalski wrote:
> Igor Mammedov wrote:
> > Changelog:
> >    * split out debug patch into a separate one with extra printk added
> >    * fixed inverte bus->self check (probably a reason why it didn't 
> > work before)
> >
> >
> > 1/3 debug patch
> > 2/3 offending patch
> > 3/3 potential fix
> >    I added more files to trace, add following to kernel CLI
> >     dyndbg="file drivers/pci/access.c +p; file 
> > drivers/pci/hotplug/acpiphp_glue.c +p; file drivers/pci/bus.c +p; 
> > file drivers/pci/pci.c +p; file drivers/pci/setup-bus.c +p; file 
> > drivers/acpi/bus.c +p" ignore_loglevel
> >
> > should be applied on top of
> >     e8afd0d9fccc PCI: pciehp: Cancel bringup sequence if card is not 
> > present
> >
> > apply a patch one by one and run testcase + capture dmesg after each 
> > patch
> > one shpould endup with 3 dmesg to ananlyse
> >   1st - old behaviour - no crash
> >   2nd - crash
> >   3rd - no crash hopefully
> >
> > Igor Mammedov (3):
> >    acpiphp: extra debug hack
> >    PCI: acpiphp: Reassign resources on bridge if necessary
> >    acpipcihp: use __pci_bus_assign_resources() if bus doesn't have 
> > bridge
> >
> >   drivers/pci/hotplug/acpiphp_glue.c | 23 ++++++++++++++++++-----
> >   1 file changed, 18 insertions(+), 5 deletions(-)
> Actually applying patch1 is already creating the crash (why???), hence 
> I have added also dmesg-6.5-0.txt which shows a working condition 
> based on git e8afd0d9fccc level (acpiphp_glue in kernel 6.4)
>
> Patch3 did not fix the issue, it seems that the culprit is somewhere 
> else triggered by  "benign" patch1 :-(
>
> Also note about the trigger description in patch3: the dmesg trace on 
> Inspiron laptop is collected after the first wake from suspend to ram. 
> The consecutive  attempt to sleep results in a frozen system.
>
> Thanks, Woody
I think that in patch1 there is a problem in your debug statement 
acpi_handle_debug(...slot_name...) - it is masking the "old" issue.
when I commented out that line in hotplug_event(), it has worked ok (as 
was expected). I will redo the testing in ~2 hours...

Woody