From: Adam Ford <aford173@gmail.com>
To: Leonard Crestez <leonard.crestez@nxp.com>
Cc: Jacky Bai <ping.bai@nxp.com>, Stephen Boyd <sboyd@kernel.org>,
Chanwoo Choi <cw00.choi@samsung.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Viresh Kumar <viresh.kumar@linaro.org>,
Michael Turquette <mturquette@baylibre.com>,
Angus Ainslie <angus@akkea.ca>,
Alexandre Bailon <abailon@baylibre.com>,
Matthias Kaehlcke <mka@chromium.org>,
Abel Vesa <abel.vesa@nxp.com>,
Saravana Kannan <saravanak@google.com>,
Krzysztof Kozlowski <krzk@kernel.org>,
linux-clk <linux-clk@vger.kernel.org>,
MyungJoo Ham <myungjoo.ham@samsung.com>,
dl-linux-imx <linux-imx@nxp.com>,
devicetree <devicetree@vger.kernel.org>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
Martin Kepplinger <martink@posteo.de>,
Silvano Di Ninno <silvano.dininno@nxp.com>,
arm-soc <linux-arm-kernel@lists.infradead.org>,
Aisheng Dong <aisheng.dong@nxp.com>,
Anson Huang <anson.huang@nxp.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Kyungmin Park <kyungmin.park@samsung.com>,
Sascha Hauer <kernel@pengutronix.de>,
Fabio Estevam <fabio.estevam@nxp.com>,
Shawn Guo <shawnguo@kernel.org>,
Georgi Djakov <georgi.djakov@linaro.org>
Subject: Re: [PATCH v7 0/5] PM / devfreq: Add dynamic scaling for imx8m ddr controller
Date: Wed, 18 Dec 2019 10:42:59 -0600 [thread overview]
Message-ID: <CAHCN7xLOgh+E5Gw+2v4RUuZANHa+CkW=ACHL5NALMcSRfRY8eQ@mail.gmail.com> (raw)
In-Reply-To: <VI1PR04MB702379645745FB697033FE6BEE530@VI1PR04MB7023.eurprd04.prod.outlook.com>
On Wed, Dec 18, 2019 at 10:22 AM Leonard Crestez
<leonard.crestez@nxp.com> wrote:
>
> On 18.12.2019 17:37, Adam Ford wrote:
> > On Wed, Dec 18, 2019 at 9:16 AM Leonard Crestez <leonard.crestez@nxp.com> wrote:
> >>
> >> On 18.12.2019 17:05, Adam Ford wrote:
> >>> On Wed, Dec 18, 2019 at 8:44 AM Leonard Crestez <leonard.crestez@nxp.com> wrote:
> >>>>
> >>>> On 18.12.2019 15:35, Adam Ford wrote:
> >>>>> On Fri, Nov 22, 2019 at 3:45 PM Leonard Crestez <leonard.crestez@nxp.com> wrote:
> >>>>>>
> >>>>>> This adds support for dynamic scaling of the DDR Controller (ddrc)
> >>>>>> present on i.MX8M series chips. Actual frequency switching is
> >>>>>> implemented inside TF-A, this driver wraps the SMC calls and
> >>>>>> synchronizes the clk tree.
> >>>>>>
> >>>>>> DRAM frequency switching requires clock manipulation but during this operation
> >>>>>> DRAM itself is briefly inaccessible so this operation is performed a SMC call
> >>>>>> to by TF-A which runs from a SRAM area. Upon returning to linux the clock tree
> >>>>>> is updated to correspond to hardware configuration.
> >>>>>>
> >>>>>> This is handled via CLK_GET_RATE_NO_CACHE for dividers but muxes are handled
> >>>>>> manually: the driver will prepare/enable the new parents ahead of switching (so
> >>>>>> that the expected roots are enabled) and afterwards it will call clk_set_parent
> >>>>>> to ensure the parents in clock framework are up-to-date.
> >>>>>>
> >>>>>> This series is useful standalone and roughly similar to devfreq drivers for
> >>>>>> tegra and rockchip.
> >>>>>>
> >>>>>> Running at lower dram rates saves power but can affect the functionality of
> >>>>>> other blocks in the chip (display, vpu etc). Support for in-kernel constraints
> >>>>>> will some separately.
> >>>>>>
> >>>>>> This series has no dependencies outside linux-next. The driver depends
> >>>>>> on features from the NXP branch of TF-A and will cleanly fail to probe
> >>>>>> on mainline. There are also plans to upstream dram dvfs in TF-A.
> >>>>>>
> >>>>>> Leonard Crestez (5):
> >>>>>> clk: imx8m: Set CLK_GET_RATE_NOCACHE on dram clocks
> >>>>>> clk: imx: Mark dram pll on 8mm and 8mn with CLK_GET_RATE_NOCACHE
> >>>>>> dt-bindings: memory: Add bindings for imx8m ddr controller
> >>>>>> PM / devfreq: Add dynamic scaling for imx8m ddr controller
> >>>>>> arm64: dts: imx8m: Add ddr controller nodes
> >>>>>>
> >>>>>> .../memory-controllers/fsl/imx8m-ddrc.yaml | 72 +++
> >>>>>> arch/arm64/boot/dts/freescale/imx8mm-evk.dts | 18 +
> >>>>>> arch/arm64/boot/dts/freescale/imx8mm.dtsi | 10 +
> >>>>>> .../boot/dts/freescale/imx8mn-ddr4-evk.dts | 18 +
> >>>>>> arch/arm64/boot/dts/freescale/imx8mn.dtsi | 10 +
> >>>>>> arch/arm64/boot/dts/freescale/imx8mq-evk.dts | 24 +
> >>>>>> arch/arm64/boot/dts/freescale/imx8mq.dtsi | 10 +
> >>>>>> drivers/clk/imx/clk-imx8mm.c | 11 +-
> >>>>>> drivers/clk/imx/clk-imx8mn.c | 12 +-
> >>>>>> drivers/clk/imx/clk-imx8mq.c | 12 +-
> >>>>>> drivers/clk/imx/clk-pll14xx.c | 7 +
> >>>>>> drivers/clk/imx/clk.h | 1 +
> >>>>>> drivers/devfreq/Kconfig | 9 +
> >>>>>
> >>>>> Since there is a Kconfig change, should there me a defconfig change?
> >>>>
> >>>> Yes, you need to enable CONFIG_ARM_IMX8M_DDRC_DEVFREQ in order to test
> >>>> this. Enabling as "m" should work.
> >>>
> >>> I enabled it as 'm' but I was more curious to know if we should push
> >>> this upstream with the rest of the series.
> >>
> >> I skipped enabling because it's very experimental; maybe after imx
> >> interconnect is also enabled?
> >>
> >>>>>> drivers/devfreq/Makefile | 1 +
> >>>>>> drivers/devfreq/imx8m-ddrc.c | 465 ++++++++++++++++++
> >>>>>> 15 files changed, 670 insertions(+), 10 deletions(-)
> >>>>>> create mode 100644 Documentation/devicetree/bindings/memory-controllers/fsl/imx8m-ddrc.yaml
> >>>>>> create mode 100644 drivers/devfreq/imx8m-ddrc.c
> >>>>>
> >>>>> I applied the whole series against 5.5-rc1 and I am trying to test it.
> >>>>> I know the 4.14 kernel NXP posted on Code Aurora is capable to
> >>>>> lowering the DDRC controller to 25MHz on the 8MM when the video is
> >>>>> off. Since there is no video support yet for the 8MM, I was expecting
> >>>>> to see the DDRC clock to be at or around 25MHz.
> >>>>>
> >>>>> Using debug FS, I can see the dram core clock is still running at
> >>>>> 750MHz, and measuring power, it shows something consistent with what I
> >>>>> see on the Code Aurora kernel with video turned on and the clock at
> >>>>> 750MHz.
> >>>>>
> >>>>> Is there some way to get the dram_core_clk to drop to 25MHz to see
> >>>>> some power reduction? The same commands used in the Yocto build don't
> >>>>> apply here since we don't have video.
> >>>>
> >>>> Current upstream driver just keeps current frequency by default. Try the
> >>>> following:
> >>>>
> >>>> cd /sys/class/devfreq/devices/devfreq0
> >>>
> >>> can't cd to /sys/class/devfreq/devices/devfreq0: No such file or directory
> >>>
> >>> I did some checking and I found:
> >>> imx8m-ddrc-devfreq 3d400000.memory-controller: failed to init
> >>> firmware freq info: -19
> >>>
> >>> Was there some prerequisite patches I needed to apply before your series?
> >>
> >> You need a recent version of TF-A from nxp ( upstream). Try this:
> >>
> >> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsource.codeaurora.org%2Fexternal%2Fimx%2Fimx-atf%2Flog%2F%3Fh%3Dimx_4.19.35_1.1.0&data=02%7C01%7Cleonard.crestez%40nxp.com%7Cc07fadd829994fe6293c08d783d02fa9%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637122802480130351&sdata=dVovGr1ttwrnSz39MPNNVg%2FB8HV5AjrHXGbksO3XvVo%3D&reserved=0
> >>
> >> Or this:
> >> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fcdleonard%2Farm-trusted-firmware%2Fcommits%2Fimx_2.0.y_busfreq&data=02%7C01%7Cleonard.crestez%40nxp.com%7Cc07fadd829994fe6293c08d783d02fa9%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637122802480140347&sdata=Q9KPq60FOxJ7GflwupNaXvbqHIR40Ej5GxeY%2BhHI658%3D&reserved=0
> >>
> >> Support on upstream ATF is not yet available
> >
> > I cloned your github branch and built it per the instructions in the
> > u-boot readme file.
> > did a make clean on u-boot, copied the bl31.bin to u-boot and rebuild
> > per U-Boot's instructions.
> >
> > U-Boot booted and Linux booted, but I still get:
> >
> > imx8m-ddrc-devfreq 3d400000.memory-controller: failed to init
> > firmware freq info: -19
>
> Which version of u-boot is that, upstream? I'm subscribed to uboot
> mailing list and I see that imx8m support has its own separate issues
> but my familiarity is limited :(
U-Boot 2020.01-rc4-00244-gf39abbbc53-dirty (Dec 18 2019 - 09:27:40 -0600)
>
> I've only ever tested with NXP uboot and the NXP version of mkimage:
>
> https://source.codeaurora.org/external/imx/uboot-imx/log/?h=imx_v2019.04_4.19.35_1.1.0
> https://source.codeaurora.org/external/imx/imx-mkimage/
I will try your versions and see what happens.
> My bootloader prints the following BuildInfo:
> - ATF 70fa7bc
>
> - U-Boot 2019.04-00019-g4d377539a119
>
Thanks for your help.
adam
> --
> Regards,
> Leonard
next prev parent reply other threads:[~2019-12-18 16:43 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-22 21:44 [PATCH v7 0/5] PM / devfreq: Add dynamic scaling for imx8m ddr controller Leonard Crestez
2019-11-22 21:45 ` [PATCH v7 1/5] clk: imx8m: Set CLK_GET_RATE_NOCACHE on dram clocks Leonard Crestez
2019-12-09 1:15 ` Shawn Guo
2019-11-22 21:45 ` [PATCH v7 2/5] clk: imx: Mark dram pll on 8mm and 8mn with CLK_GET_RATE_NOCACHE Leonard Crestez
2019-12-09 1:16 ` Shawn Guo
2019-11-22 21:45 ` [PATCH v7 3/5] dt-bindings: memory: Add bindings for imx8m ddr controller Leonard Crestez
2019-11-22 21:45 ` [PATCH v7 4/5] PM / devfreq: Add dynamic scaling " Leonard Crestez
2019-11-24 23:59 ` Chanwoo Choi
2019-11-26 19:44 ` Rob Herring
2019-11-26 23:25 ` Chanwoo Choi
2019-11-22 21:45 ` [PATCH v7 5/5] arm64: dts: imx8m: Add ddr controller nodes Leonard Crestez
2019-11-28 14:43 ` Adam Ford
2019-11-29 5:33 ` Leonard Crestez
2019-12-09 1:34 ` Shawn Guo
2019-12-18 13:35 ` [PATCH v7 0/5] PM / devfreq: Add dynamic scaling for imx8m ddr controller Adam Ford
2019-12-18 14:44 ` Leonard Crestez
2019-12-18 15:05 ` Adam Ford
2019-12-18 15:16 ` Leonard Crestez
2019-12-18 15:37 ` Adam Ford
2019-12-18 16:22 ` Leonard Crestez
2019-12-18 16:42 ` Adam Ford [this message]
[not found] ` <CAHCN7xKjpN_XEGLj-1jMG5mBbF=su67k+10frheLt+L1XaR0-g@mail.gmail.com>
2020-01-13 23:36 ` Leonard Crestez
2020-01-15 20:09 ` Adam Ford
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