Re: [PATCH] remoteproc: qcom_q6v5_mss: Fix off-by-one error in regulator error cleanup

[Dmitry Baryshkov]

On Fri, Jul 17, 2026 at 11:31:02AM +0200, Konrad Dybcio wrote:
> On 7/10/26 9:46 PM, Sailesh Nandanavanam wrote:
> > In q6v5_regulator_enable(), when any operation fails for regulator at
> > index 'i', the error cleanup path unconditionally calls
> > regulator_disable() starting from index 'i'. However, regulator 'i'
> > was never successfully enabled at this point, resulting in an
> > unbalanced disable.
> > 
> > There are three distinct failure points:
> > - regulator_set_voltage() failure: voltage was never set, load was
> > never set, regulator was never enabled.
> > - regulator_set_load() failure: voltage was set, but regulator was
> > never enabled.
> > - regulator_enable() failure: voltage and load were set, but
> > regulator was never enabled.
> > 
> > Fix this by introducing three separate error labels to handle each
> > failure point correctly. For the failing regulator at index 'i',
> > only reset the resources that were actually configured, without
> > calling regulator_disable(). Then roll back all previously enabled
> > regulators using 'i--' in the for loop initializer to skip the
> > never-enabled regulator.
> > 
> > Fixes: 19f902b53b47 ("remoteproc: qcom: Initialize and enable proxy and active regulators.")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Sailesh Nandanavanam <saileshnandanavanam@xxxxxxxxx>
> > ---
> 
> [...]
> 
> > -err:
> > -	for (; i >= 0; i--) {
> > +err_enable:
> > +	if (regs[i].uA > 0)
> > +		regulator_set_load(regs[i].reg, 0);
> > +err_set_load:
> > +	if (regs[i].uV > 0)
> > +		regulator_set_voltage(regs[i].reg, 0, INT_MAX);
> 
> The first two labels only unwind a single regulator

It is expected, the rest are unwound in the loop.

> 
> Konrad

-- 
With best wishes
Dmitry