On 1/29/20 2:37 PM, Sibi Sankar wrote:
Hey Lukasz,
Thanks for taking time to review
the series!
On 2020-01-29 15:16, Lukasz Luba wrote:
Hi Sibi,
In my opinion this solution depends on not always true assumption that
CPUFreq notification chain will be triggered when there is a frequency
This series does not create any
devfreq devices nor use the cpufreq
notification chain. It just relies
on the opening up of required-opps
from being exclusive to gen-pd using
patches 1,2,3 from patch series[1].
With the fast path disabled and
schedutil enabled, this series will
not miss any cpufreq changes.
Thank you Sibi for clarifying this. I spotted in patch 08/10
that the fast_switch is removed and the normal path is in use,
which also triggers the notification chain in CPUFreq. Then maybe other
machinery which you have put in your 'depends on' list accidentally
works thanks to this.
[1] https://patchwork.kernel.org/cover/11055499/
switch. Extending devfreq governor (as in one of the dependent patch
series that you have referred) by attaching to this notification
chain makes sense only when the SchedUtil and fast_switch is not in use.
fast_switch and cpu notifier chains
are mutually exclusive but schedutil
will still operate in the slow path
IIRC.
True, SchedUtil would work in slow_path. The driver and SoC support
'fast_switch', your solution when is properly initialized, disables it.
I would suggest to put this information in the commit message.
I don't know the side effects on the performance, though. The other
side effect would be: the CPUFreq notifications will be triggered.
The fast_switch is now the preferred way, any new ideas should
consider also this path.
The Schedutil CPUFreq governor might use the fast_switch from this
driver and the notifications will not be triggered. I have also
commented patch 08/10 which tries to disable it.
Regards,
Lukasz
On 1/27/20 8:03 PM, Sibi Sankar wrote:
This RFC series aims to extend cpu based scaling support to L3/DDR on
SDM845 and SC7180 SoCs.
Patches [1-3] - Blacklist SDM845 and SC7180 in cpufreq-dt-platdev
Patches [5-7] - Hack in a way to add/remove multiple opp tables to
a single device. I am yet to fix the debugfs to
support multiple opp_tables per device but wanted to
send what was working upstream to get an idea if multiple
opp tables per device is a feature that will be useful
upstream.
Patches [9-10] - Add the cpu/cpu-ddr/cpu-l3 opp tables for SDM845
and SC7180 SoCs.
v3:
* Migrated to using Saravana's opp-kBps bindings [1]
* Fixed some misc comments from Rajendra
* Added support for SC7180
v2:
* Incorporated Viresh's comments from:
https://lore.kernel.org/lkml/20190410102429.r6j6brm5kspmqxc3@vireshk-i7/
https://lore.kernel.org/lkml/20190410112516.gnh77jcwawvld6et@vireshk-i7/
* Dropped cpufreq-map passive governor
Git-branch: https://github.com/QuinAsura/linux/tree/lnext-012420
Some alternate ways of hosting the opp-tables:
https://github.com/QuinAsura/linux/commit/50b92bfaadc8f9a0d1e12249646e018bd6d1a9d3
https://github.com/QuinAsura/linux/commit/3d23d1eefd16ae6d9e3ef91e93e78749d8844e98
Viresh didn't really like ^^ bindings and they dont really scale
well. Just
including them here for completeness.
Depends on the following series:
[1] https://patchwork.kernel.org/cover/11277199/
[2] https://patchwork.kernel.org/cover/11055499/
[3] https://patchwork.kernel.org/cover/11326381/
Sibi Sankar (10):
arm64: dts: qcom: sdm845: Add SoC compatible to MTP
cpufreq: blacklist SDM845 in cpufreq-dt-platdev
cpufreq: blacklist SC7180 in cpufreq-dt-platdev
OPP: Add and export helper to update voltage
opp: of: export _opp_of_get_opp_desc_node
opp: Allow multiple opp_tables to be mapped to a single device
opp: Remove multiple attached opp tables from a device
cpufreq: qcom: Update the bandwidth levels on frequency change
arm64: dts: qcom: sdm845: Add cpu OPP tables
arm64: dts: qcom: sc7180: Add cpu OPP tables
arch/arm64/boot/dts/qcom/sc7180.dtsi | 287 +++++++++++++++
arch/arm64/boot/dts/qcom/sdm845-mtp.dts | 2 +-
arch/arm64/boot/dts/qcom/sdm845.dtsi | 453 ++++++++++++++++++++++++
drivers/cpufreq/cpufreq-dt-platdev.c | 2 +
drivers/cpufreq/qcom-cpufreq-hw.c | 246 +++++++++++--
drivers/opp/core.c | 111 +++++-
drivers/opp/of.c | 3 +-
drivers/opp/opp.h | 2 +
include/linux/pm_opp.h | 10 +
9 files changed, 1083 insertions(+), 33 deletions(-)
