On 7/8/22 10:19, Viresh Kumar wrote:
> On 07-07-22, 22:43, Dmitry Osipenko wrote:
>> This patch breaks Tegra again, please take a look:
>
> Damn, not again :(
>
>> OPP: Remove dev{m}_pm_opp_of_add_table_noclk()
>
> Why did you mention this patch ? This just removed an unused API,
> Tegra should have broke because of something else, isn't it ?
This patch is the cause.
>> 8<--- cut here ---
>> Unable to handle kernel paging request at virtual address ffffffff
>> [ffffffff] *pgd=9effd861, *pte=00000000, *ppte=00000000
>> Internal error: Oops: 37 [#1] PREEMPT SMP ARM
>> Modules linked in:
>> CPU: 3 PID: 8 Comm: kworker/u8:0 Not tainted
>> 5.19.0-rc1-00040-g30b62d123f4f #82
>> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
>> Workqueue: events_unbound deferred_probe_work_func
>> PC is at _opp_compare_key+0x40/0xc4
>> LR is at 0xfffffffb
>
> How is LR set to such an address ?
>
>> pc : [<c0b91b54>] lr : [<fffffffb>] psr: 20000113
>> sp : df831b08 ip : c33cd4d0 fp : df831b24
>> r10: c2586078 r9 : c258606c r8 : 00000000
>> r7 : 00000000 r6 : 00000001 r5 : c33cd480 r4 : c2586000
>> r3 : 00000000 r2 : c33cd480 r1 : c258606c r0 : c2586000
>> Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
>> Control: 10c5387d Table: 8000404a DAC: 00000051
>> ...
>> Backtrace:
>> _opp_compare_key from _set_opp+0x80/0x408
>
> Whatever happened, happened from _opp_compare_key() and I tried to
> look at it many times, couldn't figure out what's wrong there.
>
> For the device in question, pmc I think, we don't have any "opp-hz"
> property in the DT, but still the OPP core will fetch its clock and
> set clk_count to 1. But this was working earlier too, we were
> comparing the rate anyways. I think one of _opp_compare_rate() or
> _opp_compare_bw() is broken here, but I just couldn't figure out. The
> rate one should run one loop and bw one should just return. I don't
> see why a crash should come out eventually.
>
> Can you help debug this a bit ? Also see what are the values of
> opp_table->path_count and opp_table->clk_count, should be 0 and 1
> AFAICT.
I see that previously dev_pm_opp_set_config() had "_add_opp_table(dev,
false)", now it's "_add_opp_table(dev, true)".
Will take a closer look later on.
> Sorry about this Dmitry, I think we are all settled and again went
> into crap.
No problems :)
--
Best regards,
Dmitry
