Re: pmdomain: imx8m[p]-blk-ctrl: resume hangs when waking from suspended state

[Ahmad Fatoum]

Hi,

On 7/22/26 8:10 AM, Advait Dhamorikar wrote:
> Another observation I have is that if I disable the MIPI-CSI related
> nodes(MIPI-CSI, ISP, ISI), HDMI and VPU nodes from the DTS, or else
> unbind their respective drivers before suspending, the suspend
> wake sequence works just fine.
> 
> Could this indicate that the issue is related to the media clocks or the PHY
> during the suspend/resume sequence?

That might be useful info. Assuming there's a dependency that's not correctly
represented; You need to turn on power domain X (or its reset or its clock or w/e),
before power domain Y, otherwise power domain Y hangs, it would be a good next step
to find out which power domain X is the one that if you leave powered on during suspend
doesn't cause the hang.

I expect that if you take the imx8mp-blk-ctrl driver and stick an return -EBUSY into
imx8mp_blk_ctrl_power_off(), you should be able to suspend/resume cleanly (with all
DT nodes enabled and drivers normally bound).

Afterwards, you can bisect the power domains to hopefully find a particular power
domain that if skipped lets you suspend without hang. With that information,
maybe a better solution can be found.

(I am interested to hear if I am missing an easier way to do such a bisect!)

Cheers,
Ahmad


> 
> Best Regards,
> Advait
> 
> 

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