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Message-ID: <0b5e5757543d198781daf7b151a60e0b78e5b396.camel@puri.sm>
Subject: Re: [PATCH V4 07/11] arm64: dts: imx8mq: Enable both G1 and G2
 VPU's with vpu-blk-ctrl
From:   Martin Kepplinger <martin.kepplinger@puri.sm>
To:     Lucas Stach <l.stach@pengutronix.de>,
        Adam Ford <aford173@gmail.com>, linux-media@vger.kernel.org
Cc:     aford@beaconembedded.com, cphealy@gmail.com,
        kernel test robot <lkp@intel.com>,
        Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh@kernel.org>, Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-rockchip@lists.infradead.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-staging@lists.linux.dev
Date:   Mon, 23 May 2022 14:00:22 +0200
In-Reply-To: <17c5ef22479cfea3f43dce1885f6613f1bef8064.camel@pengutronix.de>
References: <20220125171129.472775-1-aford173@gmail.com>
         <20220125171129.472775-8-aford173@gmail.com>
         <d6c5c5663f8ae904d409240063295cf516e17dd1.camel@puri.sm>
         <4b958892ba788a0e9e73a9135c305aacbe33294d.camel@pengutronix.de>
         <c11a58ecc5da2e206fc2b942980223a04a103f19.camel@puri.sm>
         <17c5ef22479cfea3f43dce1885f6613f1bef8064.camel@pengutronix.de>
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Am Dienstag, dem 26.04.2022 um 12:43 +0200 schrieb Lucas Stach:
> Am Dienstag, dem 26.04.2022 um 09:38 +0200 schrieb Martin Kepplinger:
> > Am Montag, dem 25.04.2022 um 17:34 +0200 schrieb Lucas Stach:
> > > Hi Martin,
> > > 
> > > Am Montag, dem 25.04.2022 um 17:22 +0200 schrieb Martin
> > > Kepplinger:
> > > > Am Dienstag, dem 25.01.2022 um 11:11 -0600 schrieb Adam Ford:
> > > > > With the Hantro G1 and G2 now setup to run independently,
> > > > > update
> > > > > the device tree to allow both to operate.  This requires the
> > > > > vpu-blk-ctrl node to be configured.  Since vpu-blk-ctrl needs
> > > > > certain clock enabled to handle the gating of the G1 and G2
> > > > > fuses, the clock-parents and clock-rates for the various
> > > > > VPU's
> > > > > to be moved into the pgc_vpu because they cannot get re-
> > > > > parented
> > > > > once enabled, and the pgc_vpu is the highest in the chain.
> > > > > 
> > > > > Signed-off-by: Adam Ford <aford173@gmail.com>
> > > > > Reported-by: kernel test robot <lkp@intel.com>
> > > > > Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
> > > > > 
> > > > > diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > > > > b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > > > > index 2df2510d0118..549b2440f55d 100644
> > > > > --- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > > > > +++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > > > > @@ -737,7 +737,21 @@ pgc_gpu: power-domain@5 {
> > > > >                                         pgc_vpu: power-
> > > > > domain@6 {
> > > > >                                                 #power-
> > > > > domain-
> > > > > cells =
> > > > > <0>;
> > > > >                                                 reg =
> > > > > <IMX8M_POWER_DOMAIN_VPU>;
> > > > > -                                               clocks =
> > > > > <&clk
> > > > > IMX8MQ_CLK_VPU_DEC_ROOT>;
> > > > > +                                               clocks =
> > > > > <&clk
> > > > > IMX8MQ_CLK_VPU_DEC_ROOT>,
> > > > > +                                                       
> > > > > <&clk
> > > > > IMX8MQ_CLK_VPU_G1_ROOT>,
> > > > > +                                                       
> > > > > <&clk
> > > > > IMX8MQ_CLK_VPU_G2_ROOT>;
> > > > > +                                               assigned-
> > > > > clocks =
> > > > > <&clk IMX8MQ_CLK_VPU_G1>,
> > > > > +                                                            
> > > > >     
> > > > > <&clk IMX8MQ_CLK_VPU_G2>,
> > > > > +                                                            
> > > > >     
> > > > > <&clk IMX8MQ_CLK_VPU_BUS>,
> > > > > +                                                            
> > > > >     
> > > > > <&clk IMX8MQ_VPU_PLL_BYPASS>;
> > > > > +                                               assigned-
> > > > > clock-
> > > > > parents = <&clk IMX8MQ_VPU_PLL_OUT>,
> > > > > +                                                            
> > > > >     
> > > > >     
> > > > >     <&clk IMX8MQ_VPU_PLL_OUT>,
> > > > > +                                                            
> > > > >     
> > > > >     
> > > > >     <&clk IMX8MQ_SYS1_PLL_800M>,
> > > > > +                                                            
> > > > >     
> > > > >     
> > > > >     <&clk IMX8MQ_VPU_PLL>;
> > > > > +                                               assigned-
> > > > > clock-
> > > > > rates
> > > > > = <600000000>,
> > > > > +                                                            
> > > > >     
> > > > >     
> > > > >   <600000000>,
> > > > > +                                                            
> > > > >     
> > > > >     
> > > > >   <800000000>,
> > > > > +                                                            
> > > > >     
> > > > >     
> > > > >   <0>;
> > > > >                                         };
> > > > >  
> > > > >                                         pgc_disp:
> > > > > power-domain@7
> > > > > {
> > > > > @@ -1457,30 +1471,31 @@ usb3_phy1: usb-phy@382f0040 {
> > > > >                         status = "disabled";
> > > > >                 };
> > > > >  
> > > > > -               vpu: video-codec@38300000 {
> > > > > -                       compatible = "nxp,imx8mq-vpu";
> > > > > -                       reg = <0x38300000 0x10000>,
> > > > > -                             <0x38310000 0x10000>,
> > > > > -                             <0x38320000 0x10000>;
> > > > > -                       reg-names = "g1", "g2", "ctrl";
> > > > > -                       interrupts = <GIC_SPI 7
> > > > > IRQ_TYPE_LEVEL_HIGH>,
> > > > > -                                    <GIC_SPI 8
> > > > > IRQ_TYPE_LEVEL_HIGH>;
> > > > > -                       interrupt-names = "g1", "g2";
> > > > > +               vpu_g1: video-codec@38300000 {
> > > > > +                       compatible = "nxp,imx8mq-vpu-g1";
> > > > > +                       reg = <0x38300000 0x10000>;
> > > > > +                       interrupts = <GIC_SPI 7
> > > > > IRQ_TYPE_LEVEL_HIGH>;
> > > > > +                       clocks = <&clk
> > > > > IMX8MQ_CLK_VPU_G1_ROOT>;
> > > > > +                       power-domains = <&vpu_blk_ctrl
> > > > > IMX8MQ_VPUBLK_PD_G1>;
> > > > > +               };
> > > > > +
> > > > > +               vpu_g2: video-codec@38310000 {
> > > > > +                       compatible = "nxp,imx8mq-vpu-g2";
> > > > > +                       reg = <0x38310000 0x10000>;
> > > > > +                       interrupts = <GIC_SPI 8
> > > > > IRQ_TYPE_LEVEL_HIGH>;
> > > > > +                       clocks = <&clk
> > > > > IMX8MQ_CLK_VPU_G2_ROOT>;
> > > > > +                       power-domains = <&vpu_blk_ctrl
> > > > > IMX8MQ_VPUBLK_PD_G2>;
> > > > > +               };
> > > > > +
> > > > > +               vpu_blk_ctrl: blk-ctrl@38320000 {
> > > > > +                       compatible = "fsl,imx8mq-vpu-blk-
> > > > > ctrl";
> > > > > +                       reg = <0x38320000 0x100>;
> > > > > +                       power-domains = <&pgc_vpu>,
> > > > > <&pgc_vpu>,
> > > > > <&pgc_vpu>;
> > > > > +                       power-domain-names = "bus", "g1",
> > > > > "g2";
> > > > >                         clocks = <&clk
> > > > > IMX8MQ_CLK_VPU_G1_ROOT>,
> > > > > -                                <&clk
> > > > > IMX8MQ_CLK_VPU_G2_ROOT>,
> > > > > -                                <&clk
> > > > > IMX8MQ_CLK_VPU_DEC_ROOT>;
> > > > > -                       clock-names = "g1", "g2", "bus";
> > > > > -                       assigned-clocks = <&clk
> > > > > IMX8MQ_CLK_VPU_G1>,
> > > > > -                                         <&clk
> > > > > IMX8MQ_CLK_VPU_G2>,
> > > > > -                                         <&clk
> > > > > IMX8MQ_CLK_VPU_BUS>,
> > > > > -                                         <&clk
> > > > > IMX8MQ_VPU_PLL_BYPASS>;
> > > > > -                       assigned-clock-parents = <&clk
> > > > > IMX8MQ_VPU_PLL_OUT>,
> > > > > -                                                <&clk
> > > > > IMX8MQ_VPU_PLL_OUT>,
> > > > > -                                                <&clk
> > > > > IMX8MQ_SYS1_PLL_800M>,
> > > > > -                                                <&clk
> > > > > IMX8MQ_VPU_PLL>;
> > > > > -                       assigned-clock-rates = <600000000>,
> > > > > <600000000>,
> > > > > -                                              <800000000>,
> > > > > <0>;
> > > > > -                       power-domains = <&pgc_vpu>;
> > > > > +                                <&clk
> > > > > IMX8MQ_CLK_VPU_G2_ROOT>;
> > > > > +                       clock-names = "g1", "g2";
> > > > > +                       #power-domain-cells = <1>;
> > > > >                 };
> > > > >  
> > > > >                 pcie0: pcie@33800000 {
> > > > 
> > > > With this update, when testing suspend to ram on imx8mq, I get:
> > > > 
> > > > buck4: failed to disable: -ETIMEDOUT
> > > > 
> > > > where buck4 is power-supply of pgc_vpu. And thus the transition
> > > > to
> > > > suspend (and resuming) fails.
> > > > 
> > > > Have you tested system suspend after the imx8m-blk-ctrl update
> > > > on
> > > > imx8mq?
> > > 
> > > I haven't tested system suspend, don't know if anyone else did.
> > > However
> > > I guess that this is just uncovering a preexisting issue in the
> > > system
> > > suspend sequencing, which you would also hit if the video
> > > decoders
> > > were
> > > active at system suspend time.
> > > 
> > > My guess is that the regulator disable fails, due to the power
> > > domains
> > > being disabled quite late in the suspend sequence, where i2c
> > > communication with the PMIC is no longer possible due to i2c
> > > being
> > > suspended already or something like that. Maybe you can dig in a
> > > bit
> > > on
> > > the actual sequence on your system and we can see how we can
> > > rework
> > > things to suspend the power domains at a time where communication
> > > with
> > > the PMIC is still possible?
> > 
> > What exactly would you like to see? Here's all gpcv2 regulators
> > disabling on suspend. (gpu (domain 5) is disabled by runtime pm
> > often):
> > 
> > [   47.138700] imx-pgc imx-pgc-domain.5: disabling regulator
> > [   47.298071] Freezing user space processes ... (elapsed 0.008
> > seconds) done.
> > [   47.313432] OOM killer disabled.
> > [   47.316670] Freezing remaining freezable tasks ... (elapsed
> > 2.221
> > seconds) done.
> > [   49.672052] imx8m-blk-ctrl 38320000.blk-ctrl:
> > imx8m_blk_ctrl_suspend
> > start
> > [   49.704417] imx-pgc imx-pgc-domain.0: disabling regulator
> > [   49.711114] imx-pgc imx-pgc-domain.6: disabling regulator
> > [   49.819064] buck4: failed to disable: -ETIMEDOUT
> > 
> > The stack looks pretty much the same for all of them, from
> > pm_suspend()
> > over genpd_suspend_noiry().
> 
> So the GPU domain is already suspended before the system suspend,
> probably due to short runtime PM timeouts.
> 
> Can you please check at which point the i2c subsystem is suspended? I
> think we are already past that point when running the PM domain
> suspend
> from a _noirq callback. I'll take a look on how we can properly
> change
> this ordering.
> 
> Regards,
> Lucas
> 

hi Lucas, just to update a bit: (I rmmod hantro_vpu because it adds
another bug but let's ignore for now) when I use a mainline kernel and
for testing just ignore ETIMEDOUT in gpcv2 on regulator_disable():

-                               return ret;
+                               if (ret == -ETIMEDOUT)
+                                       ret = 0;
+                               else
+                                       return ret;

I see the error message the first time I suspend. Not the consecutive
times (and the systems seems to be working after resuming).

Now what's weird is when I suspend and resume often, after some time,
resume will definitely fail. Not sure yet where, but when I add debug
output for the kernel/ directory, that's usually about where it hangs:

[  969.620825] OOM killer enabled.
[  969.623971] Restarting tasks ... 
[  969.624230] systemd-udevd left refrigerator
[  969.624535] khugepaged left refrigerator
[  969.624568] gdbus left refrigerator
[  969.624795] alsa-sink-308b0 left refrigerator
[  969.626864] pipewire left refrigerator
[  969.626880] alsa-source-308 left refrigerator
[  969.626913] alsa-source-300 left refrigerator
[  969.626920] gmain left refrigerator
[  969.626949] gvfs-afc-volume left refrigerator
[  969.626949] systemd left refrigerator
[  969.626977] gmain left refrigerator
[  969.627009] chatty left refrigerator
[  969.627036] gmain left refrigerator
[  969.627060] gmain left refrigerator
[  969.627087] gmain left refrigerator

And the above hang ("sometimes") happens for "platform" in pm_test
already, so I guess it's purely a linux bug.

just so you know, in case that tells you anything more...

thanks,

                         martin