On 23-03-27 17:17:28, Saravana Kannan wrote: > On Mon, Mar 27, 2023 at 12:38 PM Abel Vesa <abel.vesa@xxxxxxxxxx> wrote: > > > > There have been already a couple of tries to make the genpd "disable > > unused" late initcall skip the powering off of domains that might be > > needed until later on (i.e. until some consumer probes). The conclusion > > was that the provider could return -EBUSY from the power_off callback > > until the provider's sync state has been reached. This patch series tries > > to provide a proof-of-concept that is working on Qualcomm platforms. > > I'm giving my thoughts in the cover letter instead of spreading it > around all the patches so that there's context between the comments. > > 1) Why can't all the logic in this patch series be implemented at the > framework level? And then allow the drivers to opt into this behavior > by setting the sync_state() callback. > > That way, you can land it only for QC drivers by setting up > sync_state() callback only for QC drivers, but actually have the same > code function correctly for non-QC drivers too. And then once we have > this functionality working properly for QC drivers for one kernel > version (or two), we'll just have the framework set the device's > driver's sync_state() if it doesn't have one already. I think Ulf has already NACK'ed that approach here: [1] https://lore.kernel.org/lkml/CAPDyKFon35wcQ+5kx3QZb-awN_S_q8y1Sir-G+GoxkCvpN=iiA@xxxxxxxxxxxxxx/ And suggested this new approach that this patch series proposes. (Unless I missunderstood his point) > > 2) sync_state() is not just about power on/off. It's also about the > power domain level. Can you handle that too please? Well, this patchset only tries to delay the disabling of unused power domains until all consumers have had a chance to probe. So we use sync state only to queue up a power-off request to make sure those unused ones get disabled. > > 3) In your GDSC drivers, it's not clear to me if you are preventing > power off until sync_state() only for GDSCs that were already on at > boot. So if an off-at-boot GDSC gets turned on, and then you attempt > to turn it off before all its consumers have probed, it'll fail to > power it off even though that wasn't necessary? I think we can circumvent looking at a GDSC by knowing it there was ever a power on request since boot. I'll try to come up with something in the new version. > > 4) The returning -EBUSY when a power off is attempted seems to be > quite wasteful. The framework will go through the whole sequence of > trying to power down, send the notifications and then fail and then > send the undo notifications. Combined with point (2) I think this can > be handled better at the aggregation level in the framework to avoid > even going that far into the power off sequence. Again, have a look at [1] (above). Ulf, any thoughts on this 4th point? > > -Saravana > > > > > I've been doing extensive testing on SM8450, but I've also spinned this > > on my X13s (SC8280XP). Both patches that add the sync state callback to > > the SC8280XP and SM8450 are here to provide context. Once we agree on > > the form, I intend to add the sync state callback to all gdsc providers. > > > > Currently, some of the gdsc providers might not reach sync state due to > > list of consumers not probing yet (or at all). The sync state can be > > enforced by writing 1 to the state_synced sysfs attribute of the > > provider, thanks to Saravana's commit [1] which has been already merged. > > > > [1] https://lore.kernel.org/r/20230304005355.746421-3-saravanak@xxxxxxxxxx > > > > V2 (RFC) of this patchset was here: > > https://lore.kernel.org/all/20230320134217.1685781-1-abel.vesa@xxxxxxxxxx/ > > > > Changes since v2: > > * renamed genpd_queue_power_off_work to pm_genpd_queue_power_off and added > > comment about its purpose w.r.t. it being exported. > > * added the qcom_cc generic sync state callback to all providers that > > register GDSCs, instead of SM8450 and SC8280XP > > > > Changes since v1: > > * Added the qcom_cc sync state callback which calls in turn the gdsc one > > * dropped extra semicolon from pm_domain.h > > > > Abel Vesa (4): > > PM: domains: Allow power off queuing from providers > > soc: qcom: rpmhpd: Do proper power off when state synced > > clk: qcom: gdsc: Avoid actual power off until sync state > > clk: qcom: Add sync state callback to all providers > > > > drivers/base/power/domain.c | 18 ++++++++++-------- > > drivers/clk/qcom/apss-ipq6018.c | 1 + > > drivers/clk/qcom/camcc-sc7180.c | 1 + > > drivers/clk/qcom/camcc-sc7280.c | 1 + > > drivers/clk/qcom/camcc-sdm845.c | 1 + > > drivers/clk/qcom/camcc-sm6350.c | 1 + > > drivers/clk/qcom/camcc-sm8250.c | 1 + > > drivers/clk/qcom/camcc-sm8450.c | 1 + > > drivers/clk/qcom/common.c | 19 +++++++++++++++++++ > > drivers/clk/qcom/common.h | 2 ++ > > drivers/clk/qcom/dispcc-qcm2290.c | 1 + > > drivers/clk/qcom/dispcc-sc7180.c | 1 + > > drivers/clk/qcom/dispcc-sc7280.c | 1 + > > drivers/clk/qcom/dispcc-sc8280xp.c | 1 + > > drivers/clk/qcom/dispcc-sdm845.c | 1 + > > drivers/clk/qcom/dispcc-sm6115.c | 1 + > > drivers/clk/qcom/dispcc-sm6125.c | 1 + > > drivers/clk/qcom/dispcc-sm6350.c | 1 + > > drivers/clk/qcom/dispcc-sm6375.c | 1 + > > drivers/clk/qcom/dispcc-sm8250.c | 1 + > > drivers/clk/qcom/dispcc-sm8450.c | 1 + > > drivers/clk/qcom/dispcc-sm8550.c | 1 + > > drivers/clk/qcom/gcc-apq8084.c | 1 + > > drivers/clk/qcom/gcc-ipq806x.c | 1 + > > drivers/clk/qcom/gcc-ipq8074.c | 1 + > > drivers/clk/qcom/gcc-mdm9615.c | 1 + > > drivers/clk/qcom/gcc-msm8660.c | 1 + > > drivers/clk/qcom/gcc-msm8909.c | 1 + > > drivers/clk/qcom/gcc-msm8916.c | 1 + > > drivers/clk/qcom/gcc-msm8939.c | 1 + > > drivers/clk/qcom/gcc-msm8953.c | 1 + > > drivers/clk/qcom/gcc-msm8960.c | 1 + > > drivers/clk/qcom/gcc-msm8974.c | 1 + > > drivers/clk/qcom/gcc-msm8976.c | 1 + > > drivers/clk/qcom/gcc-msm8994.c | 1 + > > drivers/clk/qcom/gcc-msm8996.c | 1 + > > drivers/clk/qcom/gcc-msm8998.c | 1 + > > drivers/clk/qcom/gcc-qcm2290.c | 1 + > > drivers/clk/qcom/gcc-qcs404.c | 1 + > > drivers/clk/qcom/gcc-qdu1000.c | 1 + > > drivers/clk/qcom/gcc-sa8775p.c | 1 + > > drivers/clk/qcom/gcc-sc7180.c | 1 + > > drivers/clk/qcom/gcc-sc7280.c | 1 + > > drivers/clk/qcom/gcc-sc8180x.c | 1 + > > drivers/clk/qcom/gcc-sc8280xp.c | 1 + > > drivers/clk/qcom/gcc-sdm660.c | 1 + > > drivers/clk/qcom/gcc-sdm845.c | 1 + > > drivers/clk/qcom/gcc-sdx55.c | 1 + > > drivers/clk/qcom/gcc-sdx65.c | 1 + > > drivers/clk/qcom/gcc-sm6115.c | 1 + > > drivers/clk/qcom/gcc-sm6125.c | 1 + > > drivers/clk/qcom/gcc-sm6350.c | 1 + > > drivers/clk/qcom/gcc-sm6375.c | 1 + > > drivers/clk/qcom/gcc-sm7150.c | 1 + > > drivers/clk/qcom/gcc-sm8150.c | 1 + > > drivers/clk/qcom/gcc-sm8250.c | 1 + > > drivers/clk/qcom/gcc-sm8350.c | 1 + > > drivers/clk/qcom/gcc-sm8450.c | 1 + > > drivers/clk/qcom/gcc-sm8550.c | 1 + > > drivers/clk/qcom/gdsc.c | 26 ++++++++++++++++++++++++++ > > drivers/clk/qcom/gdsc.h | 6 ++++++ > > drivers/clk/qcom/gpucc-msm8998.c | 1 + > > drivers/clk/qcom/gpucc-sc7180.c | 1 + > > drivers/clk/qcom/gpucc-sc7280.c | 1 + > > drivers/clk/qcom/gpucc-sc8280xp.c | 1 + > > drivers/clk/qcom/gpucc-sdm660.c | 1 + > > drivers/clk/qcom/gpucc-sdm845.c | 1 + > > drivers/clk/qcom/gpucc-sm6115.c | 1 + > > drivers/clk/qcom/gpucc-sm6125.c | 1 + > > drivers/clk/qcom/gpucc-sm6350.c | 1 + > > drivers/clk/qcom/gpucc-sm6375.c | 1 + > > drivers/clk/qcom/gpucc-sm8150.c | 1 + > > drivers/clk/qcom/gpucc-sm8250.c | 1 + > > drivers/clk/qcom/gpucc-sm8350.c | 1 + > > drivers/clk/qcom/lcc-ipq806x.c | 1 + > > drivers/clk/qcom/lpassaudiocc-sc7280.c | 1 + > > drivers/clk/qcom/lpasscc-sc7280.c | 1 + > > drivers/clk/qcom/lpasscorecc-sc7180.c | 2 ++ > > drivers/clk/qcom/lpasscorecc-sc7280.c | 2 ++ > > drivers/clk/qcom/mmcc-apq8084.c | 1 + > > drivers/clk/qcom/mmcc-msm8974.c | 1 + > > drivers/clk/qcom/mmcc-msm8994.c | 1 + > > drivers/clk/qcom/mmcc-msm8996.c | 1 + > > drivers/clk/qcom/mmcc-msm8998.c | 1 + > > drivers/clk/qcom/mmcc-sdm660.c | 1 + > > drivers/clk/qcom/videocc-sc7180.c | 1 + > > drivers/clk/qcom/videocc-sc7280.c | 1 + > > drivers/clk/qcom/videocc-sdm845.c | 1 + > > drivers/clk/qcom/videocc-sm8150.c | 1 + > > drivers/clk/qcom/videocc-sm8250.c | 1 + > > drivers/soc/qcom/rpmhpd.c | 19 +++++++------------ > > include/linux/pm_domain.h | 4 ++++ > > 92 files changed, 161 insertions(+), 20 deletions(-) > > > > -- > > 2.34.1 > >
