| Message ID | 20180528154228.2403116-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 28/05/18 16:41, Arnd Bergmann wrote: > When the arm-cci driver is enabled, but both CONFIG_ARM_CCI5xx_PMU and > CONFIG_ARM_CCI400_PMU are not, we get a warning about how parts of > the driver are never used: > > drivers/perf/arm-cci.c:1454:29: error: 'cci_pmu_models' defined but not used [-Werror=unused-variable] > drivers/perf/arm-cci.c:693:16: error: 'cci_pmu_event_show' defined but not used [-Werror=unused-function] > drivers/perf/arm-cci.c:685:16: error: 'cci_pmu_format_show' defined but not used [-Werror=unused-function] > > Marking all three functions as __maybe_unused avoids the warnings in > randconfig builds. I'm doing this lacking any ideas for a better fix. Yeah, it's a bit of a silly configuration to allow building a driver supporting no PMU types, but I couldn't find a way to enforce "at least one sub-option enabled" logic without introducing mutually-exclusive dependencies which kbuild thinks are recursive. An alternative would be to remove the CCI400/CCI5x0 configurability altogether - I've not not looked in detail at how much difference that actually makes. Otherwise, as an immediate quick-fix: Reviewed-by: Robin Murphy <robin.murphy@arm.com> Thanks, Robin. > Fixes: 3de6be7a3dd8 ("drivers/bus: Split Arm CCI driver") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > drivers/perf/arm-cci.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c > index e6fadc8e1178..0d09d8e669cd 100644 > --- a/drivers/perf/arm-cci.c > +++ b/drivers/perf/arm-cci.c > @@ -120,9 +120,9 @@ enum cci_models { > > static void pmu_write_counters(struct cci_pmu *cci_pmu, > unsigned long *mask); > -static ssize_t cci_pmu_format_show(struct device *dev, > +static ssize_t __maybe_unused cci_pmu_format_show(struct device *dev, > struct device_attribute *attr, char *buf); > -static ssize_t cci_pmu_event_show(struct device *dev, > +static ssize_t __maybe_unused cci_pmu_event_show(struct device *dev, > struct device_attribute *attr, char *buf); > > #define CCI_EXT_ATTR_ENTRY(_name, _func, _config) \ > @@ -1451,7 +1451,7 @@ static int cci_pmu_offline_cpu(unsigned int cpu) > return 0; > } > > -static struct cci_pmu_model cci_pmu_models[] = { > +static __maybe_unused struct cci_pmu_model cci_pmu_models[] = { > #ifdef CONFIG_ARM_CCI400_PMU > [CCI400_R0] = { > .name = "CCI_400", >
On Tue, May 29, 2018 at 04:34:01PM +0100, Robin Murphy wrote: > On 28/05/18 16:41, Arnd Bergmann wrote: > >When the arm-cci driver is enabled, but both CONFIG_ARM_CCI5xx_PMU and > >CONFIG_ARM_CCI400_PMU are not, we get a warning about how parts of > >the driver are never used: > > > >drivers/perf/arm-cci.c:1454:29: error: 'cci_pmu_models' defined but not used [-Werror=unused-variable] > >drivers/perf/arm-cci.c:693:16: error: 'cci_pmu_event_show' defined but not used [-Werror=unused-function] > >drivers/perf/arm-cci.c:685:16: error: 'cci_pmu_format_show' defined but not used [-Werror=unused-function] > > > >Marking all three functions as __maybe_unused avoids the warnings in > >randconfig builds. I'm doing this lacking any ideas for a better fix. > > Yeah, it's a bit of a silly configuration to allow building a driver > supporting no PMU types, but I couldn't find a way to enforce "at least one > sub-option enabled" logic without introducing mutually-exclusive > dependencies which kbuild thinks are recursive. > > An alternative would be to remove the CCI400/CCI5x0 configurability > altogether - I've not not looked in detail at how much difference that > actually makes. > > Otherwise, as an immediate quick-fix: > > Reviewed-by: Robin Murphy <robin.murphy@arm.com> I'll pick this one up into the arm perf tree. Will
diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c index e6fadc8e1178..0d09d8e669cd 100644 --- a/drivers/perf/arm-cci.c +++ b/drivers/perf/arm-cci.c @@ -120,9 +120,9 @@ enum cci_models { static void pmu_write_counters(struct cci_pmu *cci_pmu, unsigned long *mask); -static ssize_t cci_pmu_format_show(struct device *dev, +static ssize_t __maybe_unused cci_pmu_format_show(struct device *dev, struct device_attribute *attr, char *buf); -static ssize_t cci_pmu_event_show(struct device *dev, +static ssize_t __maybe_unused cci_pmu_event_show(struct device *dev, struct device_attribute *attr, char *buf); #define CCI_EXT_ATTR_ENTRY(_name, _func, _config) \ @@ -1451,7 +1451,7 @@ static int cci_pmu_offline_cpu(unsigned int cpu) return 0; } -static struct cci_pmu_model cci_pmu_models[] = { +static __maybe_unused struct cci_pmu_model cci_pmu_models[] = { #ifdef CONFIG_ARM_CCI400_PMU [CCI400_R0] = { .name = "CCI_400",
When the arm-cci driver is enabled, but both CONFIG_ARM_CCI5xx_PMU and CONFIG_ARM_CCI400_PMU are not, we get a warning about how parts of the driver are never used: drivers/perf/arm-cci.c:1454:29: error: 'cci_pmu_models' defined but not used [-Werror=unused-variable] drivers/perf/arm-cci.c:693:16: error: 'cci_pmu_event_show' defined but not used [-Werror=unused-function] drivers/perf/arm-cci.c:685:16: error: 'cci_pmu_format_show' defined but not used [-Werror=unused-function] Marking all three functions as __maybe_unused avoids the warnings in randconfig builds. I'm doing this lacking any ideas for a better fix. Fixes: 3de6be7a3dd8 ("drivers/bus: Split Arm CCI driver") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/perf/arm-cci.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)