Re: [PATCH] spi: imx: Revert "spi: imx: enable runtime pm support"

[Sascha Hauer]

On Fri, Oct 09, 2020 at 09:48:29AM +0200, Christian Eggers wrote:
> Hi Sascha,
> 
> On Friday, 9 October 2020, 09:39:44 CEST, Sascha Hauer wrote:
> > On Fri, Oct 09, 2020 at 06:27:38AM +0200, Christian Eggers wrote:
> > > This reverts commit 525c9e5a32bd7951eae3f06d9d077fea51718a6c.
> > >
> > > If CONFIG_PM is disabled, the system completely freezes on probe as
> > > nothing enables the clock of the SPI peripheral.
> >
> > Instead of reverting it, why not just fix it?
> I expect that 5.9 will be released soon. I think that in this late stage
> reverting is more safe than fixing...
> 
> > Normally the device should be brought to active state manually in probe
> > before pm_runtime takes over, then CONFIG_PM disabled doesn't hurt.
> > Using pm_runtime to put the device to active state initially has the
> > problem you describe.
> Thanks for the hint. I've no experience in runtime power management. If you
> could provide a patch against the current version, I can make a quick test. I
> can also try to fix it myself, but this will take until next week.

Here we go. The patch basically works, but I am also not very confident
with pm_runtime, so please have a close look ;)

Sascha

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