* [PATCH] drivers/bus: arm-cci: fix build warnings
@ 2018-05-28 15:41 Arnd Bergmann
2018-05-29 15:34 ` Robin Murphy
0 siblings, 1 reply; 3+ messages in thread
From: Arnd Bergmann @ 2018-05-28 15:41 UTC (permalink / raw)
To: Will Deacon, Mark Rutland
Cc: Arnd Bergmann, Robin Murphy, Punit Agrawal, Rob Herring,
Marc Zyngier, linux-arm-kernel, linux-kernel
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(-)
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",
--
2.9.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] drivers/bus: arm-cci: fix build warnings
2018-05-28 15:41 [PATCH] drivers/bus: arm-cci: fix build warnings Arnd Bergmann
@ 2018-05-29 15:34 ` Robin Murphy
2018-05-29 15:42 ` Will Deacon
0 siblings, 1 reply; 3+ messages in thread
From: Robin Murphy @ 2018-05-29 15:34 UTC (permalink / raw)
To: Arnd Bergmann, Will Deacon, Mark Rutland
Cc: Punit Agrawal, Rob Herring, Marc Zyngier, linux-arm-kernel, linux-kernel
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",
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] drivers/bus: arm-cci: fix build warnings
2018-05-29 15:34 ` Robin Murphy
@ 2018-05-29 15:42 ` Will Deacon
0 siblings, 0 replies; 3+ messages in thread
From: Will Deacon @ 2018-05-29 15:42 UTC (permalink / raw)
To: Robin Murphy
Cc: Arnd Bergmann, Mark Rutland, Punit Agrawal, Rob Herring,
Marc Zyngier, linux-arm-kernel, linux-kernel
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
^ permalink raw reply [flat|nested] 3+ messages in thread
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