[BUG] Rockchip SPI: Runtime PM usage count underflow!

[Vicente Bergas]

On Mon, Aug 19, 2024 at 2:49 PM Vicente Bergas <vicencb at gmail.com> wrote:
>
> On Mon, Aug 19, 2024 at 4:12 AM Vicente Bergas <vicencb at gmail.com> wrote:
> >
> > On Sun, Aug 18, 2024 at 8:13 PM Vicente Bergas <vicencb at gmail.com> wrote:
> > >
> > > Hi,
> > > i am a user of the CONFIG_SPI_SPIDEV device.
> > > It stopped working between 6.8 and 6.10.5.
> > > The SPI bus itself reports no errors to userspace, but no devices
> > > appear connected to the bus.
> > > The platform used is RK3328.
> > > The only spi-related message in dmesg is:
> > > rockchip-spi ff190000.spi: Runtime PM usage count underflow!
> > >
> > > Please, can somebody review this issue?
> > >
> > > Regards,
> > >   Vicente.
> >
> > I've tried to bisect, but there is some strange behaviour:
> > The message "Runtime PM usage count underflow!" can also appear on a
> > good kernel.
> > In order to have a reasoble iteration speed, i am updating the kernel via kexec.
> > If a good kernel (6.6.30) is cold-booted, then, all the kernels
> > kexec'd from it work too.
> > If a bad kernel (6.10.5) is cold-booted, then a 6.6.30 is kexec'd and
> > then the same 6.10.5 is kexec'd it becomes a good one.
>
> Added:
> Huang-Huang Bao <i at eh5.me>
> Linus Walleij <linus.walleij at linaro.org>
> Sasha Levin <sashal at kernel.org>
>
> The first offending commit is:
> 29d8101fb9442544077e68e27839a1979f85633d pinctrl: rockchip: fix pinmux
> bits for RK3328 GPIO2-B pins
>
> I've also tested 6.10.6 with it reverted (and
> 456447ff1fe3c28e2fd7b57a79650f62245c6428 and
> 7127c68c76f120367b9a5053f524df0b603d4a48 as dependencies) and SPI
> works fine.

Sorry for the noise:
reverting only 29d8101fb9442544077e68e27839a1979f85633d makes it work on 6.10.6.
Ignore what i said about 456447ff1fe3c28e2fd7b57a79650f62245c6428 and
7127c68c76f120367b9a5053f524df0b603d4a48.

> Regards,
>   Vicente.