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Message-ID: <1564106851.15438.1.camel@mtksdaap41>
Subject: Re: [PATCH v6 14/14] arm64: dts: Add power controller device node
 of MT8183
From:   CK Hu <ck.hu@mediatek.com>
To:     Weiyi Lu <weiyi.lu@mediatek.com>
CC:     Nicolas Boichat <drinkcat@chromium.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Rob Herring <robh@kernel.org>,
        James Liao <jamesjj.liao@mediatek.com>,
        <srv_heupstream@mediatek.com>, <linux-kernel@vger.kernel.org>,
        Fan Chen <fan.chen@mediatek.com>,
        <linux-mediatek@lists.infradead.org>,
        Yong Wu <yong.wu@mediatek.com>,
        <linux-arm-kernel@lists.infradead.org>
Date:   Fri, 26 Jul 2019 10:07:31 +0800
In-Reply-To: <1563854772.6751.11.camel@mtksdaap41>
References: <1560998286-9189-1-git-send-email-weiyi.lu@mediatek.com>
         <1560998286-9189-15-git-send-email-weiyi.lu@mediatek.com>
         <1561971461.12937.8.camel@mtksdaap41> <1563178045.17756.5.camel@mtksdaap41>
         <1563181637.6212.1.camel@mtksdaap41> <1563241851.796.7.camel@mtksdaap41>
         <1563854772.6751.11.camel@mtksdaap41>
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Hi, Weiyi:

On Tue, 2019-07-23 at 12:06 +0800, Weiyi Lu wrote:
> On Tue, 2019-07-16 at 09:50 +0800, CK Hu wrote:
> > Hi, Weiyi:
> > 
> > On Mon, 2019-07-15 at 17:07 +0800, Weiyi Lu wrote:
> > > On Mon, 2019-07-15 at 16:07 +0800, CK Hu wrote:
> > > > Hi, Weiyi:
> > > > 
> > > > On Mon, 2019-07-01 at 16:57 +0800, CK Hu wrote:
> > > > > Hi, Weiyi:
> > > > > 
> > > > > On Thu, 2019-06-20 at 10:38 +0800, Weiyi Lu wrote:
> > > > > > Add power controller node and smi-common node for MT8183
> > > > > > In scpsys node, it contains clocks and regmapping of
> > > > > > infracfg and smi-common for bus protection.
> > > > > > 
> > > > > > Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
> > > > > > ---
> > > > > >  arch/arm64/boot/dts/mediatek/mt8183.dtsi | 62 ++++++++++++++++++++++++++++++++
> > > > > >  1 file changed, 62 insertions(+)
> > > > > > 
> > > > > > diff --git a/arch/arm64/boot/dts/mediatek/mt8183.dtsi b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
> > > > > > index 08274bf..75c4881 100644
> > > > > > --- a/arch/arm64/boot/dts/mediatek/mt8183.dtsi
> > > > > > +++ b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
> > > > > > @@ -8,6 +8,7 @@
> > > > > >  #include <dt-bindings/clock/mt8183-clk.h>
> > > > > >  #include <dt-bindings/interrupt-controller/arm-gic.h>
> > > > > >  #include <dt-bindings/interrupt-controller/irq.h>
> > > > > > +#include <dt-bindings/power/mt8183-power.h>
> > > > > >  
> > > > > >  / {
> > > > > >  	compatible = "mediatek,mt8183";
> > > > > > @@ -196,6 +197,62 @@
> > > > > >  			#clock-cells = <1>;
> > > > > >  		};
> > > > > >  
> > > > > > +		scpsys: syscon@10006000 {
> > > > > > +			compatible = "mediatek,mt8183-scpsys", "syscon";
> > > > > > +			#power-domain-cells = <1>;
> > > > > > +			reg = <0 0x10006000 0 0x1000>;
> > > > > > +			clocks = <&topckgen CLK_TOP_MUX_AUD_INTBUS>,
> > > > > > +				 <&infracfg CLK_INFRA_AUDIO>,
> > > > > > +				 <&infracfg CLK_INFRA_AUDIO_26M_BCLK>,
> > > > > > +				 <&topckgen CLK_TOP_MUX_MFG>,
> > > > > > +				 <&topckgen CLK_TOP_MUX_MM>,
> > > > > > +				 <&topckgen CLK_TOP_MUX_CAM>,
> > > > > > +				 <&topckgen CLK_TOP_MUX_IMG>,
> > > > > > +				 <&topckgen CLK_TOP_MUX_IPU_IF>,
> > > > > > +				 <&topckgen CLK_TOP_MUX_DSP>,
> > > > > > +				 <&topckgen CLK_TOP_MUX_DSP1>,
> > > > > > +				 <&topckgen CLK_TOP_MUX_DSP2>,
> > > > > > +				 <&mmsys CLK_MM_SMI_COMMON>,
> > > > > > +				 <&mmsys CLK_MM_SMI_LARB0>,
> > > > > > +				 <&mmsys CLK_MM_SMI_LARB1>,
> > > > > > +				 <&mmsys CLK_MM_GALS_COMM0>,
> > > > > > +				 <&mmsys CLK_MM_GALS_COMM1>,
> > > > > > +				 <&mmsys CLK_MM_GALS_CCU2MM>,
> > > > > > +				 <&mmsys CLK_MM_GALS_IPU12MM>,
> > > > > > +				 <&mmsys CLK_MM_GALS_IMG2MM>,
> > > > > > +				 <&mmsys CLK_MM_GALS_CAM2MM>,
> > > > > > +				 <&mmsys CLK_MM_GALS_IPU2MM>,
> > > > 
> > > > I've removed all mmsys clock in scpsys node and display still works, so
> > > > I think these subsys clock could be removed from scpsys node. It's
> > > > reasonable that subsys clock is controlled by subsys device or the
> > > > device use it. In MT2712 [1], the scpsys does not control subsys clock
> > > > and it works, so I think you should remove subsys clock in scpsys device
> > > > node.
> > > > 
> > > > [1]
> > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/mediatek/mt2712e.dtsi?h=v5.2
> > > > 
> > > > Regards,
> > > > CK
> > > > 
> > > 
> > > Hello CK,
> > > 
> > > Sorry, I can't agree with you at all.
> > > I thought you just created an environment where the MM (DISP) power
> > > domain could not be turned on and off properly.
> > > If you delete those mmsys clocks listed, bus protection will not work.
> > > These clocks are used for bus protection that I mentioned in patch [2].
> > > I guess you are now trying to solve the problem that mmsys blocks are
> > > used for probing two drivers. One for the display and another for the
> > > clock. Right?
> > > In the previous test you mentioned, you have affected the registration
> > > of mmsys clock first. This is why you saw the boot failure. I think boot
> > > failure is the real problem I should avoid if mmsys clock cannot probe.
> > > 
> > > [2] https://patchwork.kernel.org/patch/11005747/
> > > 
> > 
> > OK, I'll try another way to fix the probe problem, but I still have
> > question about bus protection. I'm not sure how bus protection works,
> > but I think that what mtk_scpsys_ext_clear_bus_protection() do could be
> > moved in mtk_smi_clk_enable(). How do you think?
> > 
> > Regards,
> > CK
> > 
> 
> I think we need to consider the disable case as well.
> And SMI may not be the only DISP power domain user. As far as I know and
> being requested, bus protection should only be set when DISP power
> domain is going to be turned OFF, and vise versa.
> But if SMI will turn ON before all the other multimedia drivers and be
> the last one to turn OFF DISP power domain, it might be worth trying.

I would like to try it, but how could I know bus protection still works
after modification?

Regards,
CK

> 
> > > > 
> > > > > 
> > > > > Up to now, MT8183 mmsys has the same resource with another device node:
> > > > > 
> > > > > 		mmsys: syscon@14000000 {
> > > > > 			compatible = "mediatek,mt8183-mmsys", "syscon";
> > > > > 			reg = <0 0x14000000 0 0x1000>;
> > > > > 			#clock-cells = <1>;
> > > > > 		};
> > > > > 
> > > > > 		display_components: dispsys@14000000 {
> > > > > 			compatible = "mediatek,mt8183-display";
> > > > > 			reg = <0 0x14000000 0 0x1000>;
> > > > > 			power-domains = <&scpsys MT8183_POWER_DOMAIN_DISP>;
> > > > > 		};
> > > > > 
> > > > > I think this two node should be merge into one node, so I've try to
> > > > > merge them:
> > > > > 
> > > > > 		mmsys: syscon@14000000 {
> > > > > 			compatible = "mediatek,mt8183-mmsys", "syscon";
> > > > > 			reg = <0 0x14000000 0 0x1000>;
> > > > > 			power-domains = <&scpsys MT8183_POWER_DOMAIN_DISP>;
> > > > > 			#clock-cells = <1>;
> > > > > 		};
> > > > > 
> > > > > But I got a kernel panic when boot,
> > > > > 
> > > > > [    3.458523] Unable to handle kernel paging request at virtual address
> > > > > fffffffffffffdfb
> > > > > [    3.466999] Mem abort info:
> > > > > [    3.470116]   ESR = 0x96000005
> > > > > [    3.473268]   Exception class = DABT (current EL), IL = 32 bits
> > > > > [    3.479375]   SET = 0, FnV = 0
> > > > > [    3.482530]   EA = 0, S1PTW = 0
> > > > > [    3.485785] Data abort info:
> > > > > [    3.488831]   ISV = 0, ISS = 0x00000005
> > > > > [    3.493067]   CM = 0, WnR = 0
> > > > > [    3.496229] swapper pgtable: 4k pages, 39-bit VAs, pgdp =
> > > > > 000000004f8fa26d
> > > > > [    3.503214] [fffffffffffffdfb] pgd=0000000000000000,
> > > > > pud=0000000000000000
> > > > > [    3.510408] Internal error: Oops: 96000005 [#1] PREEMPT SMP
> > > > > [    3.515974] Modules linked in:
> > > > > [    3.519023] Process kworker/0:3 (pid: 106, stack limit =
> > > > > 0x00000000281d0651)
> > > > > [    3.526066] CPU: 0 PID: 106 Comm: kworker/0:3 Tainted: G        W
> > > > > 4.19.43 #208
> > > > > [    3.533974] Hardware name: MediaTek kukui rev1 board (DT)
> > > > > [    3.539374] Workqueue: events deferred_probe_work_func
> > > > > [    3.544507] pstate: 20000005 (nzCv daif -PAN -UAO)
> > > > > [    3.549294] pc : clk_prepare+0x18/0x40
> > > > > [    3.553038] lr : scpsys_clk_enable+0x40/0xb4
> > > > > [    3.557299] sp : ffffff800855b9e0
> > > > > [    3.560606] x29: ffffff800855b9f0 x28: ffffff93e1e5f594
> > > > > [    3.565911] x27: 000000000000000f x26: ffffff93e1e5e9b8
> > > > > [    3.571217] x25: 000000003b9aca00 x24: ffffff800858530c
> > > > > [    3.576522] x23: ffffffffffffffff x22: fffffffffffffdfb
> > > > > [    3.581827] x21: 000000000000000a x20: ffffffccb89aafc8
> > > > > [    3.587132] x19: fffffffffffffdfb x18: 00005a5c77082016
> > > > > [    3.592438] x17: 0000000000000400 x16: 0000000000000001
> > > > > [    3.597743] x15: 0000000000000009 x14: ffffff93e271c908
> > > > > [    3.603048] x13: 0000000000000b22 x12: 0000000000000008
> > > > > [    3.608353] x11: 0000000001d063de x10: 0000000000000008
> > > > > [    3.613659] x9 : 00000000ffffffed x8 : 0000000000000000
> > > > > [    3.618964] x7 : 736d6c2dff7224fe x6 : 0000008000000000
> > > > > [    3.624269] x5 : 0000000000000000 x4 : 0000000080000000
> > > > > [    3.629575] x3 : 002f6d6e74000000 x2 : 0000000000000000
> > > > > [    3.634880] x1 : 000000000000000a x0 : fffffffffffffdfb
> > > > > [    3.640185] Call trace:
> > > > > [    3.642625]  clk_prepare+0x18/0x40
> > > > > [    3.646019]  scpsys_clk_enable+0x40/0xb4
> > > > > [    3.649935]  scpsys_power_on+0x13c/0x304
> > > > > [    3.653850]  scpsys_probe+0xe0/0x5fc
> > > > > [    3.657419]  platform_drv_probe+0x80/0xb0
> > > > > [    3.661420]  really_probe+0x114/0x28c
> > > > > [    3.665075]  driver_probe_device+0x64/0xfc
> > > > > [    3.669164]  __device_attach_driver+0xb8/0xd0
> > > > > [    3.673513]  bus_for_each_drv+0x88/0xd0
> > > > > [    3.677341]  __device_attach+0xac/0x130
> > > > > [    3.681169]  device_initial_probe+0x20/0x2c
> > > > > [    3.685344]  bus_probe_device+0x34/0x90
> > > > > [    3.689172]  deferred_probe_work_func+0x74/0xac
> > > > > [    3.693698]  process_one_work+0x210/0x420
> > > > > [    3.697700]  worker_thread+0x278/0x3e4
> > > > > [    3.701443]  kthread+0x11c/0x12c
> > > > > [    3.704665]  ret_from_fork+0x10/0x18
> > > > > 
> > > > > I'm not really understand what happen, but scpsys and mmsys point to
> > > > > each other in MT8183. Why these two node point to each other in MT8183?
> > > > > If this is really hardware limitation, we need to solve this in driver.
> > > > > If this is not a hardware limitation, I would like to re-organize device
> > > > > tree to prevent this problem.
> > > > > 
> > > > > Regards,
> > > > > CK
> > > > > 
> > > > > 
> > > > > > +				 <&imgsys CLK_IMG_LARB5>,
> > > > > > +				 <&imgsys CLK_IMG_LARB2>,
> > > > > > +				 <&camsys CLK_CAM_LARB6>,
> > > > > > +				 <&camsys CLK_CAM_LARB3>,
> > > > > > +				 <&camsys CLK_CAM_SENINF>,
> > > > > > +				 <&camsys CLK_CAM_CAMSV0>,
> > > > > > +				 <&camsys CLK_CAM_CAMSV1>,
> > > > > > +				 <&camsys CLK_CAM_CAMSV2>,
> > > > > > +				 <&camsys CLK_CAM_CCU>,
> > > > > > +				 <&ipu_conn CLK_IPU_CONN_IPU>,
> > > > > > +				 <&ipu_conn CLK_IPU_CONN_AHB>,
> > > > > > +				 <&ipu_conn CLK_IPU_CONN_AXI>,
> > > > > > +				 <&ipu_conn CLK_IPU_CONN_ISP>,
> > > > > > +				 <&ipu_conn CLK_IPU_CONN_CAM_ADL>,
> > > > > > +				 <&ipu_conn CLK_IPU_CONN_IMG_ADL>;
> > > > > > +			clock-names = "audio", "audio1", "audio2",
> > > > > > +				      "mfg", "mm", "cam",
> > > > > > +				      "isp", "vpu", "vpu1",
> > > > > > +				      "vpu2", "vpu3", "mm-0",
> > > > > > +				      "mm-1", "mm-2", "mm-3",
> > > > > > +				      "mm-4", "mm-5", "mm-6",
> > > > > > +				      "mm-7", "mm-8", "mm-9",
> > > > > > +				      "isp-0", "isp-1", "cam-0",
> > > > > > +				      "cam-1", "cam-2", "cam-3",
> > > > > > +				      "cam-4", "cam-5", "cam-6",
> > > > > > +				      "vpu-0", "vpu-1", "vpu-2",
> > > > > > +				      "vpu-3", "vpu-4", "vpu-5";
> > > > > > +			infracfg = <&infracfg>;
> > > > > > +			smi_comm = <&smi_common>;
> > > > > > +		};
> > > > > > +
> > > > > >  		apmixedsys: syscon@1000c000 {
> > > > > >  			compatible = "mediatek,mt8183-apmixedsys", "syscon";
> > > > > >  			reg = <0 0x1000c000 0 0x1000>;
> > > > > > @@ -260,6 +317,11 @@
> > > > > >  			#clock-cells = <1>;
> > > > > >  		};
> > > > > >  
> > > > > > +		smi_common: smi@14019000 {
> > > > > > +			compatible = "mediatek,mt8183-smi-common", "syscon";
> > > > > > +			reg = <0 0x14019000 0 0x1000>;
> > > > > > +		};
> > > > > > +
> > > > > >  		imgsys: syscon@15020000 {
> > > > > >  			compatible = "mediatek,mt8183-imgsys", "syscon";
> > > > > >  			reg = <0 0x15020000 0 0x1000>;
> > > > > 
> > > > 
> > > > 
> > > 
> > > 
> > 
> > 
> 
>