linux-kernel - Re: [PATCH 0/5] pmdomain: Restore behaviour for disabling unused PM domains

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Message-Id: <DCPDDIZ3S1CM.3DJYY5U4T6V4U@cknow.org>
Date: Wed, 10 Sep 2025 21:33:04 +0200
From: "Diederik de Haas" <didi.debian@...ow.org>
To: "Ulf Hansson" <ulf.hansson@...aro.org>, "Geert Uytterhoeven"
 <geert@...ux-m68k.org>, "Nicolas Frattaroli"
 <nicolas.frattaroli@...labora.com>, "Saravana Kannan"
 <saravanak@...gle.com>, <linux-pm@...r.kernel.org>
Cc: "Stephen Boyd" <sboyd@...nel.org>, "Rafael J . Wysocki"
 <rafael@...nel.org>, "Heiko Stuebner" <heiko@...ech.de>, "Sebastian
 Reichel" <sebastian.reichel@...labora.com>, "Sebin Francis"
 <sebin.francis@...com>, "Bjorn Andersson" <andersson@...nel.org>, "Abel
 Vesa" <abel.vesa@...aro.org>, "Peng Fan" <peng.fan@....nxp.com>, "Tomi
 Valkeinen" <tomi.valkeinen@...asonboard.com>, "Johan Hovold"
 <johan@...nel.org>, "Maulik Shah" <maulik.shah@....qualcomm.com>, "Michal
 Simek" <michal.simek@....com>, "Konrad Dybcio" <konradybcio@...nel.org>,
 "Thierry Reding" <thierry.reding@...il.com>, "Jonathan Hunter"
 <jonathanh@...dia.com>, <linux-arm-kernel@...ts.infradead.org>,
 <linux-kernel@...r.kernel.org>, <linux-rockchip@...ts.infradead.org>,
 "Christian Hewitt" <christianshewitt@...il.com>
Subject: Re: [PATCH 0/5] pmdomain: Restore behaviour for disabling unused PM
 domains

Hi,

On Tue Sep 9, 2025 at 1:11 PM CEST, Ulf Hansson wrote:
> Recent changes to genpd prevents those PM domains being powered-on during
> initialization from being powered-off during the boot sequence. Based upon
> whether CONFIG_PM_CONFIG_PM_GENERIC_DOMAINS_OF is set of not, genpd relies
> on the sync_state mechanism or the genpd_power_off_unused() (which is a
> late_initcall_sync), to understand when it's okay to allow these PM domains
> to be powered-off.
>
> This new behaviour in genpd has lead to problems on different platforms [1].
>
> In this series, I am therefore suggesting to restore the behavior of
> genpd_power_off_unused() along with introducing a new genpd config flag,
> GENPD_FLAG_NO_STAY_ON, to allow genpd OF providers to opt-out from the new
> behaviour.

Is it expected that I'm still seeing this on a Rock64 (rk3328), just
like before [1]?

  [   17.124202] rockchip-pm-domain ff100000.syscon:power-controller: sync_state() pending due to ff300000.gpu
  [   17.129799] rockchip-pm-domain ff100000.syscon:power-controller: sync_state() pending due to ff350000.video-codec
  [   17.140003] rockchip-pm-domain ff100000.syscon:power-controller: sync_state() pending due to ff360000.video-codec

This is with a 6.17-rc5 kernel with this patch set applied.
And it also has this patch from Christian Hewitt added, now in v3:
https://lore.kernel.org/linux-rockchip/20250906120810.1833016-1-christianshewitt@gmail.com/

When I boot into a 6.17-rc5 kernel without any patches applied, I do get
the 2 for ff350000.video-codec and ff360000.video-codec, but not the 
ff300000.gpu one.

Interestingly:
ff300000.gpu -> power-domains = <&power RK3328_PD_GPU>;
ff350000.video-codec -> power-domains = <&power RK3328_PD_VPU>;
ff360000.video-codec -> power-domains = <&power RK3328_PD_VIDEO>;

I would be surprised if that was a coincidence.

Cheers,
  Diederik

[1] https://lore.kernel.org/all/DCK0O99SYSCF.BMBAEUV24C1G@cknow.org/

>
> Kind regards
> Ulf Hansson
>
> [1]
> https://lore.kernel.org/all/20250701114733.636510-1-ulf.hansson@linaro.org/
> https://lore.kernel.org/all/20250902-rk3576-lockup-regression-v1-1-c4a0c9daeb00@collabora.com/
>
> Ulf Hansson (5):
>   pmdomain: core: Restore behaviour for disabling unused PM domains
>   pmdomain: rockchip: Fix regulator dependency with
>     GENPD_FLAG_NO_STAY_ON
>   pmdomain: renesas: rcar-sysc: Don't keep unused PM domains powered-on
>   pmdomain: renesas: rcar-gen4-sysc: Don't keep unused PM domains
>     powered-on
>   pmdomain: renesas: rmobile-sysc: Don't keep unused PM domains
>     powered-on
>
>  drivers/pmdomain/core.c                   | 20 ++++++++++++++------
>  drivers/pmdomain/renesas/rcar-gen4-sysc.c |  1 +
>  drivers/pmdomain/renesas/rcar-sysc.c      |  1 +
>  drivers/pmdomain/renesas/rmobile-sysc.c   |  3 ++-
>  drivers/pmdomain/rockchip/pm-domains.c    |  2 +-
>  include/linux/pm_domain.h                 |  7 +++++++
>  6 files changed, 26 insertions(+), 8 deletions(-)

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