Devfreq looks for unsupported frequencies on Exynos

Devfreq looks for unsupported frequencies on Exynos

[Krzysztof Kozlowski]

Hi All,

I noticed recently error logs when booting Odroid HC1 (Exynos5422) on
exynos_defconfig, 5.4.0-rc1-next-20191004:

[    5.168786] exynos-bus: new bus device registered: soc:bus_wcore ( 84000 KHz ~ 400000 KHz)
[    5.177022] exynos-bus: new bus device registered: soc:bus_noc ( 67000 KHz ~ 100000 KHz)
[    5.184705] exynos-bus: new bus device registered: soc:bus_fsys_apb (100000 KHz ~ 200000 KHz)
[    5.192903] exynos-bus: new bus device registered: soc:bus_fsys (100000 KHz ~ 200000 KHz)
[    5.201414] exynos-bus: new bus device registered: soc:bus_fsys2 ( 75000 KHz ~ 150000 KHz)
[    5.209986] exynos-bus: new bus device registered: soc:bus_mfc ( 96000 KHz ~ 333000 KHz)
[    5.217931] exynos-bus: new bus device registered: soc:bus_gen ( 89000 KHz ~ 267000 KHz)
[    5.225222] exynos-bus soc:bus_wcore: dev_pm_opp_set_rate: failed to find current OPP for freq 532000000 (-34)
[    5.225975] exynos-bus: new bus device registered: soc:bus_peri ( 67000 KHz ~  67000 KHz)
[    5.238824] exynos-bus soc:bus_noc: dev_pm_opp_set_rate: failed to find current OPP for freq 111000000 (-34)
[    5.245719] exynos-bus: new bus device registered: soc:bus_g2d ( 84000 KHz ~ 333000 KHz)
[    5.252653] exynos-bus soc:bus_fsys_apb: dev_pm_opp_set_rate: failed to find current OPP for freq 222000000 (-34)
[    5.263518] exynos-bus: new bus device registered: soc:bus_g2d_acp ( 67000 KHz ~ 267000 KHz)
[    5.280650] exynos-bus: new bus device registered: soc:bus_jpeg ( 75000 KHz ~ 300000 KHz)
[    5.288827] exynos-bus: new bus device registered: soc:bus_jpeg_apb ( 84000 KHz ~ 167000 KHz)
[    5.296957] exynos-bus: new bus device registered: soc:bus_disp1_fimd (120000 KHz ~ 200000 KHz)
[    5.305939] exynos-bus: new bus device registered: soc:bus_disp1 (120000 KHz ~ 300000 KHz)
[    5.314036] exynos-bus: new bus device registered: soc:bus_gscl_scaler (150000 KHz ~ 300000 KHz)
[    5.323090] exynos-bus: new bus device registered: soc:bus_mscl ( 84000 KHz ~ 400000 KHz)

You can see that Exynos devfreq was trying to set 532000000 Hz for
wcore, 111000000 for noc and 222000000 for fsys_apb. These are higher
frequencies than we have in DTSI.

Any ideas why? It does not look normal...

Best regards,
Krzysztof

Re: Devfreq looks for unsupported frequencies on Exynos

[Kamil Konieczny]

On 04.10.2019 12:31, Krzysztof Kozlowski wrote:
> 
> Hi All,
> 
> I noticed recently error logs when booting Odroid HC1 (Exynos5422) on
> exynos_defconfig, 5.4.0-rc1-next-20191004:
> [...]
> [    5.225222] exynos-bus soc:bus_wcore: dev_pm_opp_set_rate: failed to find current OPP for freq 532000000 (-34)
> [    5.225975] exynos-bus: new bus device registered: soc:bus_peri ( 67000 KHz ~  67000 KHz)
> [    5.238824] exynos-bus soc:bus_noc: dev_pm_opp_set_rate: failed to find current OPP for freq 111000000 (-34)
> [    5.245719] exynos-bus: new bus device registered: soc:bus_g2d ( 84000 KHz ~ 333000 KHz)
> [    5.252653] exynos-bus soc:bus_fsys_apb: dev_pm_opp_set_rate: failed to find current OPP for freq 222000000 (-34)
> [...]
> You can see that Exynos devfreq was trying to set 532000000 Hz for
> wcore, 111000000 for noc and 222000000 for fsys_apb. These are higher
> frequencies than we have in DTSI.
> 
> Any ideas why? It does not look normal...

Thank you for report. This is known issue, clocks left by u-boot are too
high and they are not present in opp tables. Lukasz Luba sended patchset
"[PATCH v1 00/50] Exynos5x clocks and buses changes" but it should first
be made in u-boot.

I have idea for a fix and will send it soon after weekend.

-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland