Re: [PATCH v3 00/24] pmdomain: Add generic ->sync_state() support to genpd

Re: [PATCH v3 00/24] pmdomain: Add generic ->sync_state() support to genpd

[Diederik de Haas]

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Hi,

On Wed Sep 3, 2025 at 12:33 PM CEST, Ulf Hansson wrote:
> On Wed, 3 Sept 2025 at 09:39, Sebin Francis <sebin.francis@ti.com> wrote:
>> On 01/07/25 17:17, Ulf Hansson wrote:
>> >
>> > If a PM domain (genpd) is powered-on during boot, there is probably a good
>> > reason for it. Therefore it's known to be a bad idea to allow such genpd to be
>> > powered-off before all of its consumer devices have been probed. This series
>> > intends to fix this problem.
>> >
>> > We have been discussing these issues at LKML and at various Linux-conferences
>> > in the past. I have therefore tried to include the people I can recall being
>> > involved, but I may have forgotten some (my apologies), feel free to loop them
>> > in.
>> >
>> > Please help review and test!
>>
>> During testing on a TI platform, I observed new kernel warnings after
>> applying this patch series:
>>
>> ti_sci_pm_domains 44043000.system-controller:power-controller:
>> sync_state() pending due to fd00000.gpu
>>
>> These warnings occur when a device (in this case, the GPU) has no driver
>> bound to it. The fw_devlink_dev_sync_state[0] in the core has a check
>> before printing this warning. It checks whether the device driver has a
>> sync_state handler OR the device bus has a sync_state handler in the
>> dev_has_sync_state[1]. If both conditions are false,
>> fw_devlink_dev_sync_state[0] performs an early return before printing
>> the warning.
>>
>> Before this patch series, both handlers were absent for device driver
>> ti_sci_pm_domains and the device bus, so both conditions failed and no
>> warnings were printed.
>>
>> This patch series adds a sync_state handler for the bus, which now
>> satisfies the second condition. So it doesn't do an early return and
>> proceeds to print the warning.
>
> Thanks for the report and testing!
>
> Indeed this is the new and expected behaviour. I agree that it's
> certainly questionable if those prints should be at the warning level.
>
> We should probably downgrade those to dev_info(), at least. Let me
> send a patch to see what Saravana and others are thinking about it!

I want to report that I see similar warnings on Rock64 (rk3328):

[   16.868033] rockchip-pm-domain ff100000.syscon:power-controller: sync_state() pending due to ff300000.gpu
[   16.873637] rockchip-pm-domain ff100000.syscon:power-controller: sync_state() pending due to ff350000.video-codec
[   16.896495] rockchip-pm-domain ff100000.syscon:power-controller: sync_state() pending due to ff360000.video-codec

This is with a 6.17-rc3 kernel with various rkvdec patches and in dmesg
I later see msgs wrt ff300000.gpu (lima) and ff350000.video-codec
(hantro-vpu), but not ff360000.video-codec (rkvdec). Full dmesg:
https://paste.sr.ht/~diederik/951b54ea8422756e5efaa61d6bcefb575cfe28a4

But there were also USB issues (not sure why), so I rebooted and then I
did see msgs wrt rkvdec. Full dmesg:
https://paste.sr.ht/~diederik/156f65fc6be05d02484568dfd303c46ba76b3a8e

I also have a 6.17-rc4 kernel which is clean upstream, thus without any
media patches. This time no USB issues (also no USB device plugged in)
and I see msgs wrt lima and hantro-vpu, but not rkvdec. Full dmesg:
https://paste.sr.ht/~diederik/4affea034b0c9fb522a8ad5b90e8b59b4bd856ec

What's possibly relevant is that the 6.17-rc3+unreleased kernel also has
this patch added, which adds 'power-domain@RK3328_PD_GPU' to rk3328.dtsi
https://lore.kernel.org/linux-rockchip/20250830115135.3549305-1-christianshewitt@gmail.com/

I actually found this thread because I too couldn't find the commit ID
Nicolas referenced in this post:
https://lore.kernel.org/linux-rockchip/20250902-rk3576-lockup-regression-v1-1-c4a0c9daeb00@collabora.com/

I have no idea whether it's related though (I have no rk3576 device).

I haven't tried (yet) whether the sync_state() msg is also present on
other Rockchip based devices.

Cheers,
  Diederik

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