Re: [PATCH 5/9] ARM: dts: exynos: move exynos-bus nodes out of soc in Exynos4412

On 03/02/2023 12:45, Marek Szyprowski wrote:

Hi Krzysztof,

On 29.01.2023 11:42, Krzysztof Kozlowski wrote:

quoted

On 25/01/2023 10:45, Krzysztof Kozlowski wrote:

quoted

The soc node is supposed to have only device nodes with MMIO addresses,
as reported by dtc W=1:

   exynos4412.dtsi:407.20-413.5:
     Warning (simple_bus_reg): /soc/bus-acp: missing or empty reg/ranges property

and dtbs_check:

   exynos4412-i9300.dtb: soc: bus-acp:
     {'compatible': ['samsung,exynos-bus'], 'clocks': [[7, 456]], 'clock-names': ['bus'], 'operating-points-v2': [[132]], 'status': ['okay'], 'devfreq': [[117]]} should not be valid under {'type': 'object'}

Move the bus nodes and their OPP tables out of SoC to fix this.
Re-order them alphabetically while moving and put some of the OPP tables
in device nodes (if they are not shared).

Applied.

I don't have a good news. It looks that this change is responsible for 
breaking boards that were rock-stable so far, like Odroid U3. I didn't 
manage to analyze what exactly causes the issue, but it looks that the 
exynos-bus devfreq driver somehow depends on the order of the nodes:

(before)

# dmesg | grep exynos-bus
[    6.415266] exynos-bus: new bus device registered: soc:bus-dmc 
(100000 KHz ~ 400000 KHz)
[    6.422717] exynos-bus: new bus device registered: soc:bus-acp 
(100000 KHz ~ 267000 KHz)
[    6.454323] exynos-bus: new bus device registered: soc:bus-c2c 
(100000 KHz ~ 400000 KHz)
[    6.489944] exynos-bus: new bus device registered: soc:bus-leftbus 
(100000 KHz ~ 200000 KHz)
[    6.493990] exynos-bus: new bus device registered: soc:bus-rightbus 
(100000 KHz ~ 200000 KHz)
[    6.494612] exynos-bus: new bus device registered: soc:bus-display 
(160000 KHz ~ 200000 KHz)
[    6.494932] exynos-bus: new bus device registered: soc:bus-fsys 
(100000 KHz ~ 134000 KHz)
[    6.495246] exynos-bus: new bus device registered: soc:bus-peri ( 
50000 KHz ~ 100000 KHz)
[    6.495577] exynos-bus: new bus device registered: soc:bus-mfc 
(100000 KHz ~ 200000 KHz)

(after)

# dmesg | grep exynos-bus

[    6.082032] exynos-bus: new bus device registered: bus-dmc (100000 
KHz ~ 400000 KHz)
[    6.122726] exynos-bus: new bus device registered: bus-leftbus 
(100000 KHz ~ 200000 KHz)
[    6.146705] exynos-bus: new bus device registered: bus-mfc (100000 
KHz ~ 200000 KHz)
[    6.181632] exynos-bus: new bus device registered: bus-peri ( 50000 
KHz ~ 100000 KHz)
[    6.204770] exynos-bus: new bus device registered: bus-rightbus 
(100000 KHz ~ 200000 KHz)
[    6.211087] exynos-bus: new bus device registered: bus-acp (100000 
KHz ~ 267000 KHz)
[    6.216936] exynos-bus: new bus device registered: bus-c2c (100000 
KHz ~ 400000 KHz)
[    6.225748] exynos-bus: new bus device registered: bus-display 
(160000 KHz ~ 200000 KHz)
[    6.242978] exynos-bus: new bus device registered: bus-fsys (100000 
KHz ~ 134000 KHz)

This is definitely a driver bug, but so far it worked fine, so this is a 
regression that need to be addressed somehow...

Thanks for checking, but what is exactly the bug? The devices registered
- just with different name.

Best regards,
Krzysztof


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