[PATCH v5 00/21] PM / devferq: Add generic exynos bus frequency driver and new passive governor
Tobias Jakobi
tjakobi at math.uni-bielefeld.de
Thu Mar 24 06:52:30 PDT 2016
Hello everybody,
Markus Reichl wrote:
> Hi Chanwoo,
>
> Am 24.03.2016 um 05:30 schrieb Chanwoo Choi:
>> Dear Anand and Tobias,
>>
>> To Anand,
>> First of all, thanks to your test on previous patchset.
>> I removed the your tested-by tag from this version
>> because I modified the devfreq core using DEVFREQ_TRANSITION_NOTIFIER notifier.
>> I think that this patch-set need to test with this patchset.
>> If you possible, could you please test this patch-set? Thanks in advance.
>>
>> To Tobias,
>> I fixed the following issues reported by you. Thanks your test and report.
>> - RCU locking issue
>> - debugfs error during kernel booting
>>
>> Best Regards,
>> Chanwoo Choi
>
> This set works fine on odroid U3 but gives the following with dmesg |grep devfreq:
>
> [ 2.066890] devfreq bus_dmc: Couldn't update frequency transition information.
> [ 2.190238] devfreq bus_leftbus: Couldn't update frequency transition information.
I have yet to test this new iteration of the patchset, but this message
looks familiar. I already encountered it with the older version applied
to vanilla-4.5.y.
The messages happen when devfreq_update_status() (in
drivers/devfreq/devfreq.c) encounters a uninitialized (zero)
previous_freq. I have currently fixed this in my local tree by just
skipping (goto out) devfreq_update_status() in that case.
Maybe it would be more elegant to set previous_freq to something sane on
probe. IIRC then it is set from initial_freq on probe, but the exynos
code doesn't set this one.
Maybe this info is helpful?
With best wishes,
Tobias
>
> Thanks,
> --
> Markus Reichl
>
>>
>> On 2016년 03월 24일 13:25, Chanwoo Choi wrote:
>>> Dear all,
>>>
>>> This patchset uses the DEVFREQ_TRANSITION_NOTIFIER notifier to connecth
>>> devfreq device using ondemand governor and devfreq device using passive
>>> governor. Also I fix the some issue reported by 'Tobias Jakobi' and add the
>>> detailed issue information. But, this patchset don't modify the anything of
>>> Device Tree patches (patch12 ~ patch21) which already got the reviewed-by
>>> from Exynos Soc Maintainer.
>>>
>>> I tested it on exynos3250-rinato and exynos4412-odroidu3 board.
>>>
>>> [Description]
>>> This patch-set includes the two features as following. The generic exynos bus
>>> frequency driver is able to support almost Exynos SoCs for bus frequency
>>> scaling. And the new passive governor is able to make the dependency on
>>> between devices for frequency/voltage scaling. I had posted the patch-set[1]
>>> with the similiar concept. This is is revised version for exynos bus frequency.
>>> - Generic exynos bus frequency driver
>>> - New passive governor of DEVFREQ framework
>>> [1] https://lkml.org/lkml/2015/1/7/872
>>> : [PATCHv3 0/8] devfreq: Add generic exynos memory-bus frequency driver
>>>
>>> Changes from v4:
>>> (https://lkml.org/lkml/2015/12/14/43)
>>> - Add new DEVFREQ_TRANSITION_NOTIFIER notifier. The passive
>>> devfreq device recevie the changed frequency of parent
>>> devfreq device through DEVFREQ_TRANSITION_NOTIFIER.
>>> - Add governor type to identify thme using the defined constant
>>> - Modify the passive governor using the DEVFREQ_TRANSITION_NOTIFIER notifier.
>>> - Fix the RCU locking probrlm (Reported-by: Tobias Jakobi)
>>> - Fix the debugfs error during the kernel booting (Reported-by: Tobias Jakobi)
>>>
>>> Changes from v3:
>>> (https://lkml.org/lkml/2015/12/11/75)
>>> - Add the reviewed-by tag from Krzysztof Kozlowski (patch2/3/13/14/15/16/17)
>>> - Fix typo of the description on patch14
>>> - Modify the subject and description of patch17
>>> - Reorder the 'bus_xxx' device tree node alphabetically in
>>> both exynos3250-rinato/monk.dts and exynos4412-trats/odroidu3
>>>
>>> Changes from v2:
>>> (https://lkml.org/lkml/2015/12/8/869)
>>> - Fix typo on documentation
>>> - Modify the more appropriate sentence on patch description
>>> - Add the detailed description about both parent and passive bus device
>>> - Modify the DMC frequency for Exynos4x12 DMC bus (200MHz -> 267MHz)
>>> - Modify the voltage of 200MHz was included in Exynos3250 DMC bus (800mV -> 825mV)
>>> - Rename OPP nodes as 'opp@<opp-hz>'
>>> - Delete the duplicate 'opp-microvolt' property of passive devfreq device
>>> - Reorder the 'bus_xxx' device tree node alphabetically in exynos3250-rinato/monk.dts
>>> - Reorder the 'bus_xxx' device tree node alphabetically in exynos4412-trats/odroidu3
>>> - Add new exynos4412-ppmu-common.dtsi to remove the duplicate PPMU dt node
>>> on rinato/monk/trats2/odroid-u3 board
>>> - Add the log message if bus device is registered to devfreq framework successfully
>>> - Add the reviewed-by tag from Krzysztof Kozlowski
>>> - Add the tested-by tag from Anand Moon on Odroid U3
>>> - Add 'SAMSUNG BUS FREQUENCY DRIVER' entry to MAINTAINERS
>>>
>>> Changes from v1:
>>> (https://lkml.org/lkml/2015/11/26/260)
>>> - Check whether the instance of regulator is NULL or not
>>> when executing regulator_disable() because of only parent
>>> devfreq device has the regulator instance. After fixing it,
>>> the wake-up from suspend state is well working. (patch1)
>>> - Fix bug which checks 'bus-clk' instead of 'bus->regulator'
>>> after calling devm_clk_get() (on patch1)
>>> - Update the documentation to remove the description about
>>> DEVFREQ-EVENT subsystem (on patch2)
>>> - Add the full name of DMC (Dynamic Memory Controller) (on patch2)
>>> - Modify the detailed correlation of buses for Exynos3250
>>> on documentation (patch2)
>>> - Add the MFC bus node for Exynos3250 (on patch11, patch12)
>>> - Fix the duplicate frequency of bus_display on Exynos4x12.dtsi
>>> - Add the PPMU node for exynos4412-odroidu3
>>> - Add the support of bus frequency for exynos4412-odroidu3
>>>
>>> Detailed descirption for patch-set:
>>> 1. Add generic exynos bus frequency driver
>>> : This patch-set adds the generic exynos bus frequency driver for AXI bus
>>> of sub-blocks in exynos SoC. The Samsung Exynos SoC have the common
>>> architecture for bus between DRAM and sub-blocks in SoC.
>>>
>>> There are the different buses according to Exynos SoC because Exynos SoC
>>> has the differnt sub-blocks and bus speed. In spite of this difference
>>> among Exynos SoCs, this driver is able to support almost Exynos SoC by adding
>>> unique data of each bus in the devicetree file.
>>>
>>> In devicetree, each bus node has a bus clock, regulator, operation-point
>>> and devfreq-event devices which measure the utilization of each bus block.
>>>
>>> For example,
>>> - The bus of DMC block in exynos3250.dtsi are listed below:
>>>
>>> bus_dmc: bus_dmc {
>>> compatible = "samsung,exynos-bus";
>>> clocks = <&cmu_dmc CLK_DIV_DMC>;
>>> clock-names = "bus";
>>> operating-points-v2 = <&bus_dmc_opp_table>;
>>> status = "disabled";
>>> };
>>>
>>> bus_dmc_opp_table: opp_table1 {
>>> compatible = "operating-points-v2";
>>> opp-shared;
>>>
>>> opp at 50000000 {
>>> opp-hz = /bits/ 64 <50000000>;
>>> opp-microvolt = <800000>;
>>> };
>>> opp at 100000000 {
>>> opp-hz = /bits/ 64 <100000000>;
>>> opp-microvolt = <800000>;
>>> };
>>> opp at 134000000 {
>>> opp-hz = /bits/ 64 <134000000>;
>>> opp-microvolt = <800000>;
>>> };
>>> opp at 200000000 {
>>> opp-hz = /bits/ 64 <200000000>;
>>> opp-microvolt = <825000>;
>>> };
>>> opp at 400000000 {
>>> opp-hz = /bits/ 64 <400000000>;
>>> opp-microvolt = <875000>;
>>> };
>>> };
>>>
>>> - Usage case to handle the frequency and voltage of bus on runtime
>>> in exynos3250-rinato.dts are listed below:
>>>
>>> &bus_dmc {
>>> devfreq-events = <&ppmu_dmc0_3>, <&ppmu_dmc1_3>;
>>> vdd-supply = <&buck1_reg>; /* VDD_MIF */
>>> status = "okay";
>>> };
>>>
>>> 2. Add new passive governor of DEVFREQ framework (patch5-patch7)
>>> : This patch-set add the new passive governor for DEVFREQ framework.
>>> The existing governors (ondemand, performance and so on) are used for DVFS
>>> (Dynamic Voltage and Frequency Scaling) drivers. The existing governors
>>> are independently used for specific device driver which don't give the
>>> influence to other device drviers and also don't receive the effect from
>>> other device drivers.
>>>
>>> The passive governor depends on operation of parent driver with existing
>>> governors(ondemand, performance and so on) extremely and is not able to
>>> decide the new frequency by oneself. According to the decided new frequency
>>> of parent driver with governor, the passive governor uses it to decide
>>> the appropriate frequency for own device driver. The passive governor
>>> must need the following information from device tree:
>>>
>>> For exameple,
>>> There are one more bus device drivers in Exynos3250 which need to
>>> change their source clock according to their utilization on runtime.
>>> But, they share the same power line (e.g., regulator). So, LEFTBUS bus
>>> driver is operated as parent with ondemand governor and then the rest
>>> device driver with passive governor.
>>>
>>> The buses of Internal block in exynos3250.dtsi are listed below:
>>> When LEFTBUS bus driver (parent) changes the bus frequency with
>>> ondemand governor on runtime, the rest bus devices which sharing
>>> the same power line (VDD_INT) will change the each bus frequency
>>> according to the decision of LEFTBUS bus driver (parent).
>>>
>>> - INT (Internal) block
>>> : VDD_INT |--- LEFTBUS
>>> |--- PERIL
>>> |--- MFC
>>> |--- G3D
>>> |--- RIGHTBUS
>>> |--- FSYS
>>> |--- LCD0
>>> |--- PERIR
>>> |--- ISP
>>> |--- CAM
>>>
>>> - The buss of INT block in exynos3250.dtsi are listed below:
>>> bus_leftbus: bus_leftbus {
>>> compatible = "samsung,exynos-bus";
>>> clocks = <&cmu CLK_DIV_GDL>;
>>> clock-names = "bus";
>>> operating-points-v2 = <&bus_leftbus_opp_table>;
>>> status = "disabled";
>>> };
>>>
>>> bus_rightbus: bus_rightbus {
>>> compatible = "samsung,exynos-bus";
>>> clocks = <&cmu CLK_DIV_GDR>;
>>> clock-names = "bus";
>>> operating-points-v2 = <&bus_leftbus_opp_table>;
>>> status = "disabled";
>>> };
>>>
>>> (Omit the rest bus dt node)
>>>
>>> - Usage case to handle the frequency and voltage of bus on runtime
>>> in exynos3250-rinato.dts are listed below:
>>> /* Parent bus device of VDD_INT */
>>> &bus_leftbus {
>>> devfreq-events = <&ppmu_leftbus_3>, <&ppmu_rightbus_3>;
>>> vdd-supply = <&buck3_reg>;
>>> status = "okay";
>>> };
>>>
>>> /* Passive bus device depend on LEFTBUS bus. */
>>> &bus_rightbus {
>>> devfreq = <&bus_leftbus>; /* 'devfreq' property indicates
>>> the phandle of parent device. */
>>> status = "okay";
>>> };
>>>
>>> (Omit the rest bus dt node)
>>>
>>> Chanwoo Choi (21):
>>> PM / devfreq: exynos: Add generic exynos bus frequency driver
>>> PM / devfreq: exynos: Add documentation for generic exynos bus frequency driver
>>> PM / devfreq: Add devfreq_get_devfreq_by_phandle()
>>> PM / devfreq: Add new DEVFREQ_TRANSITION_NOTIFIER notifier
>>> PM / devfreq: Add governer type with unique number
>>> PM / devfreq: Add new passive governor
>>> PM / devfreq: exynos: Add support of bus frequency of sub-blocks using passive governor
>>> PM / devfreq: exynos: Update documentation for bus devices using passive governor
>>> PM / devfreq: exynos: Add the detailed correlation between sub-blocks and power line
>>> PM / devfreq: exynos: Remove unused exynos4/5 busfreq driver
>>> MAINTAINERS: Add samsung bus frequency driver entry
>>> ARM: dts: Add DMC bus node for Exynos3250
>>> ARM: dts: Add DMC bus frequency for exynos3250-rinato/monk
>>> ARM: dts: Add bus nodes using VDD_INT for Exynos3250
>>> ARM: dts: Add bus nodes using VDD_MIF for Exynos4x12
>>> ARM: dts: Add bus nodes using VDD_INT for Exynos4x12
>>> ARM: dts: Add bus nodes using VDD_MIF for Exynos4210
>>> ARM: dts: Add exynos4412-ppmu-common dtsi to delete duplicate PPMU nodes
>>> ARM: dts: Add support of bus frequency using VDD_INT for exynos3250-rinato
>>> ARM: dts: Expand the voltage range of buck1/3 regulator for exynos4412-odroidu3
>>> ARM: dts: Add support of bus frequency for exynos4412-trats/odroidu3
>>>
>>> .../devicetree/bindings/devfreq/exynos-bus.txt | 390 ++++++++
>>> MAINTAINERS | 9 +
>>> arch/arm/boot/dts/exynos3250-monk.dts | 47 +-
>>> arch/arm/boot/dts/exynos3250-rinato.dts | 88 +-
>>> arch/arm/boot/dts/exynos3250.dtsi | 181 ++++
>>> arch/arm/boot/dts/exynos4210.dtsi | 159 +++
>>> arch/arm/boot/dts/exynos4412-odroid-common.dtsi | 56 +-
>>> arch/arm/boot/dts/exynos4412-ppmu-common.dtsi | 50 +
>>> arch/arm/boot/dts/exynos4412-trats2.dts | 88 +-
>>> arch/arm/boot/dts/exynos4x12.dtsi | 174 ++++
>>> drivers/devfreq/Kconfig | 35 +-
>>> drivers/devfreq/Makefile | 4 +-
>>> drivers/devfreq/devfreq.c | 224 ++++-
>>> drivers/devfreq/exynos-bus.c | 561 +++++++++++
>>> drivers/devfreq/exynos/Makefile | 3 -
>>> drivers/devfreq/exynos/exynos4_bus.c | 1055 --------------------
>>> drivers/devfreq/exynos/exynos4_bus.h | 110 --
>>> drivers/devfreq/exynos/exynos5_bus.c | 431 --------
>>> drivers/devfreq/exynos/exynos_ppmu.c | 119 ---
>>> drivers/devfreq/exynos/exynos_ppmu.h | 86 --
>>> drivers/devfreq/governor.h | 21 +
>>> drivers/devfreq/governor_passive.c | 192 ++++
>>> drivers/devfreq/governor_performance.c | 1 +
>>> drivers/devfreq/governor_powersave.c | 1 +
>>> drivers/devfreq/governor_simpleondemand.c | 1 +
>>> drivers/devfreq/governor_userspace.c | 1 +
>>> include/linux/devfreq.h | 70 ++
>>> 27 files changed, 2209 insertions(+), 1948 deletions(-)
>>> create mode 100644 Documentation/devicetree/bindings/devfreq/exynos-bus.txt
>>> create mode 100644 arch/arm/boot/dts/exynos4412-ppmu-common.dtsi
>>> create mode 100644 drivers/devfreq/exynos-bus.c
>>> delete mode 100644 drivers/devfreq/exynos/Makefile
>>> delete mode 100644 drivers/devfreq/exynos/exynos4_bus.c
>>> delete mode 100644 drivers/devfreq/exynos/exynos4_bus.h
>>> delete mode 100644 drivers/devfreq/exynos/exynos5_bus.c
>>> delete mode 100644 drivers/devfreq/exynos/exynos_ppmu.c
>>> delete mode 100644 drivers/devfreq/exynos/exynos_ppmu.h
>>> create mode 100644 drivers/devfreq/governor_passive.c
>>>
>>
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