soundwire qcom slimbus dependency (was Re: [PATCH 0/2] arm64 defconfig: Get faddr2line working)

[John Garry]

On 28/07/2022 13:03, Arnd Bergmann wrote:
> On Thu, Jul 28, 2022 at 1:57 PM Jonathan Marek <jonathan@xxxxxxxx> wrote:
> > On 7/28/22 5:09 AM, Arnd Bergmann wrote:
> > > diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
> > > index 22b706350ead..f65c7737c2db 100644
> > > --- a/drivers/soundwire/qcom.c
> > > +++ b/drivers/soundwire/qcom.c
> > > @@ -1289,11 +1289,7 @@ static int qcom_swrm_probe(struct platform_device *pdev)
> > >           data = of_device_get_match_data(dev);
> > >           ctrl->rows_index = sdw_find_row_index(data->default_rows);
> > >           ctrl->cols_index = sdw_find_col_index(data->default_cols);
> > > -#if IS_REACHABLE(CONFIG_SLIMBUS)
> > > -       if (dev->parent->bus == &slimbus_bus) {
> > > -#else
> > > -       if (false) {
> > > -#endif
> > > +       if (IS_ENABLED(CONFIG_SLIMBUS) && dev->parent->bus == &slimbus_bus) {
> > >                   ctrl->reg_read = qcom_swrm_ahb_reg_read;
> > >                   ctrl->reg_write = qcom_swrm_ahb_reg_write;
> > >                   ctrl->regmap = dev_get_regmap(dev->parent, NULL);
> >
> > This relies on the compiler optimizing out the reference to slimbus_bus,
> > which doesn't exist in the CONFIG_SLIMBUS=n case (not tested, but I
> > think this means an O0 build will fail?).
>
> That is correct: We rely on this everywhere in the kernel, which is why
> it is impossible to build kernels with -O0.

Was there any patch sent to fix/improve this? I could not see any. Or 
any plan to do so?

Thanks,
John