From: Abel Vesa <abel.vesa@nxp.com>
To: Chanwoo Choi <cwchoi00@gmail.com>
Cc: Rob Herring <robh@kernel.org>,
Dong Aisheng <aisheng.dong@nxp.com>,
Shawn Guo <shawnguo@kernel.org>,
Sascha Hauer <s.hauer@pengutronix.de>,
Fabio Estevam <festevam@gmail.com>,
"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
MyungJoo Ham <myungjoo.ham@samsung.com>,
Kyungmin Park <kyungmin.park@samsung.com>,
Chanwoo Choi <cw00.choi@samsung.com>,
Georgi Djakov <djakov@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Ulf Hansson <ulf.hansson@linaro.org>,
Ahmad Fatoum <a.fatoum@pengutronix.de>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
linux-serial@vger.kernel.org, NXP Linux Team <linux-imx@nxp.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
devicetree@vger.kernel.org, linux-pm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC 06/19] devfreq: imx8m-ddrc: Add late system sleep PM ops
Date: Mon, 25 Oct 2021 23:59:19 +0300 [thread overview]
Message-ID: <YXcapw5rxzkSZ0i3@ryzen> (raw)
In-Reply-To: <dbb4f5a5-e303-7df2-9d42-819a4abac98b@gmail.com>
On 21-09-15 12:37:45, Chanwoo Choi wrote:
> Hi,
>
> As I commented on patch5, you keep the OPP list on devicetree file
> and then you better to use the 'suspend_opp' property
> for setting the highest frequency during suspend/resume.
>
Hi,
I think there is no mechanism in place to ensure that the suspend opp
will be set only after all the icc users have suspended. I only tested
briefly, but I can tell you that there are cases where some icc user
asks for a different opp right after the suspend opp was set. This leads
to suspending with a different rate than the one from suspend opp.
So I guess I still need the late system sleep pm opps to circumvent such
situations.
> On 21. 9. 14. 오전 2:38, Abel Vesa wrote:
> > Seems that, in order to be able to resume from suspend, the dram rate
> > needs to be the highest one available. Therefore, add the late system
> > suspend/resume PM ops which set the highest rate on suspend and the
> > latest one used before suspending on resume.
> >
> > Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
> > ---
> > drivers/devfreq/imx8m-ddrc.c | 28 +++++++++++++++++++++++++++-
> > 1 file changed, 27 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/devfreq/imx8m-ddrc.c b/drivers/devfreq/imx8m-ddrc.c
> > index f18a5c3c1c03..f39741b4a0b0 100644
> > --- a/drivers/devfreq/imx8m-ddrc.c
> > +++ b/drivers/devfreq/imx8m-ddrc.c
> > @@ -72,6 +72,8 @@ struct imx8m_ddrc {
> > struct clk *dram_alt;
> > struct clk *dram_apb;
> > + unsigned long suspend_rate;
> > + unsigned long resume_rate;
> > int freq_count;
> > struct imx8m_ddrc_freq freq_table[IMX8M_DDRC_MAX_FREQ_COUNT];
> > };
> > @@ -271,6 +273,22 @@ static int imx8m_ddrc_target(struct device *dev, unsigned long *freq, u32 flags)
> > return ret;
> > }
> > +static int imx8m_ddrc_suspend(struct device *dev)
> > +{
> > + struct imx8m_ddrc *priv = dev_get_drvdata(dev);
> > +
> > + priv->resume_rate = clk_get_rate(priv->dram_core);
> > +
> > + return imx8m_ddrc_target(dev, &priv->suspend_rate, 0);
> > +}
> > +
> > +static int imx8m_ddrc_resume(struct device *dev)
> > +{
> > + struct imx8m_ddrc *priv = dev_get_drvdata(dev);
> > +
> > + return imx8m_ddrc_target(dev, &priv->resume_rate, 0);
> > +}
> > +
> > static int imx8m_ddrc_get_cur_freq(struct device *dev, unsigned long *freq)
> > {
> > struct imx8m_ddrc *priv = dev_get_drvdata(dev);
> > @@ -324,6 +342,9 @@ static int imx8m_ddrc_init_freq_info(struct device *dev)
> > if (dev_pm_opp_add(dev, freq->rate * 250000, 0))
> > return -ENODEV;
> > +
> > + if (index == 0)
> > + priv->suspend_rate = freq->rate * 250000;
> > }
> > return 0;
> > @@ -399,11 +420,16 @@ static const struct of_device_id imx8m_ddrc_of_match[] = {
> > };
> > MODULE_DEVICE_TABLE(of, imx8m_ddrc_of_match);
> > +static const struct dev_pm_ops imx8m_ddrc_pm_ops = {
> > + SET_LATE_SYSTEM_SLEEP_PM_OPS(imx8m_ddrc_suspend, imx8m_ddrc_resume)
> > +};
> > +
> > static struct platform_driver imx8m_ddrc_platdrv = {
> > .probe = imx8m_ddrc_probe,
> > .driver = {
> > .name = "imx8m-ddrc-devfreq",
> > - .of_match_table = imx8m_ddrc_of_match,
> > + .pm = &imx8m_ddrc_pm_ops,
> > + .of_match_table = of_match_ptr(imx8m_ddrc_of_match),
> > },
> > };
> > module_platform_driver(imx8m_ddrc_platdrv);
> >
>
>
> --
> Best Regards,
> Samsung Electronics
> Chanwoo Choi
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next prev parent reply other threads:[~2021-10-25 21:03 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-13 17:37 [RFC 00/19] Add interconnect and devfreq support for i.MX8MQ Abel Vesa
2021-09-13 17:37 ` [RFC 01/19] dt-bindings: interconnect: imx8mq: Add missing pl301 and SAI ids Abel Vesa
2021-09-15 8:09 ` Georgi Djakov
2021-09-13 17:37 ` [RFC 02/19] devfreq: imx-bus: Switch governor to powersave Abel Vesa
2021-09-13 17:37 ` [RFC 03/19] devfreq: imx-bus: Decouple imx-bus from icc made Abel Vesa
2021-09-13 17:37 ` [RFC 04/19] devfreq: imx8m-ddrc: Change governor to powersave Abel Vesa
2021-09-13 17:38 ` [RFC 05/19] devfreq: imx8m-ddrc: Use the opps acquired from EL3 Abel Vesa
2021-09-15 3:29 ` Chanwoo Choi
2021-09-15 18:12 ` Chanwoo Choi
2021-09-13 17:38 ` [RFC 06/19] devfreq: imx8m-ddrc: Add late system sleep PM ops Abel Vesa
2021-09-15 3:37 ` Chanwoo Choi
2021-10-25 20:59 ` Abel Vesa [this message]
2021-11-10 12:15 ` Martin Kepplinger
2021-11-30 20:06 ` Abel Vesa
2021-12-01 9:35 ` Martin Kepplinger
2021-12-06 12:33 ` Martin Kepplinger
2021-09-13 17:38 ` [RFC 07/19] interconnect: imx: Switch from imx_icc_node_adj_desc to fsl, icc-id node assignment Abel Vesa
2021-09-13 17:38 ` [RFC 08/19] interconnect: imx8: Remove the imx_icc_node_adj_desc Abel Vesa
2021-10-18 12:41 ` Adam Ford
2021-10-25 9:00 ` Abel Vesa
2021-09-13 17:38 ` [RFC 09/19] interconnect: imx8mq: Add the pl301_per_m and pl301_wakeup nodes and subnodes Abel Vesa
2021-09-13 17:38 ` [RFC 10/19] interconnect: imx8mq: Add of_match_table Abel Vesa
2021-09-13 17:38 ` [RFC 11/19] interconnect: imx: Add imx_icc_get_bw and imx_icc_aggregate functions Abel Vesa
2021-09-13 17:38 ` [RFC 12/19] arm64: dts: imx8mq: Add fsl,icc-id property to ddrc node Abel Vesa
2021-09-13 17:38 ` [RFC 13/19] arm64: dts: imx8mq: Add fsl,icc-id to noc node Abel Vesa
2021-09-13 17:38 ` [RFC 14/19] arm64: dts: imx8mq: Add all pl301 nodes Abel Vesa
2021-09-13 17:38 ` [RFC 15/19] arm64: dts: imx8mq: Add the interconnect node Abel Vesa
2021-09-13 17:38 ` [RFC 16/19] arm64: dts: imx8mq: Add interconnect properties to icc consumer nodes Abel Vesa
2021-09-13 17:38 ` [RFC 17/19] net: ethernet: fec_main: Add interconnect support Abel Vesa
2021-09-13 17:38 ` [RFC 18/19] mmc: sdhci-esdhc-imx: " Abel Vesa
2021-09-13 17:38 ` [RFC 19/19] arm64: defconfig: Add necessary configs for icc+devfreq on i.MX8MQ Abel Vesa
2021-09-24 10:20 ` [RFC 00/19] Add interconnect and devfreq support for i.MX8MQ Martin Kepplinger
2021-09-29 11:44 ` Abel Vesa
2021-09-30 8:03 ` Martin Kepplinger
2021-09-30 14:22 ` Abel Vesa
2021-10-05 13:34 ` Martin Kepplinger
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