[PATCH] memory: stm32_omm: fix child clock leak on set_amcr() error path

[Diego Fernando Mancera Gomez]

Without st,omm-mux, of_property_read_u32() fails and leaves mux at its
initial value of 0, so the "if (mux & CR_MUXEN)" block is skipped and
the child clocks are never enabled in stm32_omm_configure(). The new
check is then false and nothing is disabled on the set_amcr() error
path, so there is nothing to leak and no unbalanced
clk_disable_unprepare().

The cleanup uses exactly the same condition that gated
stm32_omm_toggle_child_clock(dev, true), so this also covers the case
where st,omm-mux is present but CR_MUXEN is not set. The earlier
"goto error" paths are all taken before the clocks are enabled, or
from toggle_child_clock() itself, which already unwinds on failure.

If it helps, I can send a v2 that states this in the commit message.

Best regards,
Diego


On Wed, Sep 23, 2026 at 8:54 AM Krzysztof Kozlowski <krzk at kernel.org> wrote:
>
> On 18/09/2026 01:59, Diego Fernando Mancera Gomez wrote:
> > When the mux is enabled, stm32_omm_configure() enables the two OSPI
> > child clocks via stm32_omm_toggle_child_clock(dev, true); they are meant
> > to stay enabled for the device's lifetime and are disabled again in
> > stm32_omm_remove() and on the devm_of_platform_populate() error path.
> >
> > However, if the subsequent stm32_omm_set_amcr() call fails, the function
> > jumps to the "error:" label which only calls pm_runtime_put_sync_suspend()
> > before returning, leaving the two child clocks enabled. As this happens
> > during probe, the error is propagated and .remove() is never called, so
> > the clock enable references are leaked. devm_clk_bulk_get() only releases
> > the clock handles on unwind, it does not undo clk_prepare_enable().
> >
> > Disable the child clocks on the set_amcr() error path, mirroring the
> > cleanup already done on the devm_of_platform_populate() failure path.
> >
> > Fixes: 8181d061dcff ("memory: Add STM32 Octo Memory Manager driver")
> > Cc: stable at vger.kernel.org
> > Signed-off-by: Diego Fernando Mancera Gomez <diegomancera.dev at gmail.com>
> > ---
> >  drivers/memory/stm32_omm.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/memory/stm32_omm.c b/drivers/memory/stm32_omm.c
> > index 84eb23c824f5..3599683ab04a 100644
> > --- a/drivers/memory/stm32_omm.c
> > +++ b/drivers/memory/stm32_omm.c
> > @@ -274,6 +274,8 @@ static int stm32_omm_configure(struct device *dev)
> >       writel_relaxed(omm->cr, omm->io_base + OMM_CR);
> >
> >       ret = stm32_omm_set_amcr(dev, true);
> > +     if (ret && (mux & CR_MUXEN))
> > +             stm32_omm_toggle_child_clock(dev, false);
>
> How does it work without st,omm-mux?
>
> >
> >  error:
> >       pm_runtime_put_sync_suspend(dev);
>
>
> Best regards,
> Krzysztof