| Message ID | 20190712091357.744515-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | dma: ste_dma40: fix unneeded variable warning | expand |
On Fri, Jul 12, 2019 at 11:13:30AM +0200, Arnd Bergmann wrote: > clang-9 points out that there are two variables that depending on the > configuration may only be used in an ARRAY_SIZE() expression but not > referenced: > > drivers/dma/ste_dma40.c:145:12: error: variable 'd40_backup_regs' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > static u32 d40_backup_regs[] = { > ^ > drivers/dma/ste_dma40.c:214:12: error: variable 'd40_backup_regs_chan' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > static u32 d40_backup_regs_chan[] = { > > Mark these __maybe_unused to shut up the warning. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Might be worth mentioning that this warning will only appear when CONFIG_PM is unset (they are both used in d40_save_restore_registers). Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
On Fri, Jul 12, 2019 at 10:39 AM Nathan Chancellor <natechancellor@gmail.com> wrote: > > On Fri, Jul 12, 2019 at 11:13:30AM +0200, Arnd Bergmann wrote: > > clang-9 points out that there are two variables that depending on the > > configuration may only be used in an ARRAY_SIZE() expression but not > > referenced: > > > > drivers/dma/ste_dma40.c:145:12: error: variable 'd40_backup_regs' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > > static u32 d40_backup_regs[] = { > > ^ > > drivers/dma/ste_dma40.c:214:12: error: variable 'd40_backup_regs_chan' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > > static u32 d40_backup_regs_chan[] = { > > > > Mark these __maybe_unused to shut up the warning. > > > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Thanks for the patch! > > Might be worth mentioning that this warning will only appear when > CONFIG_PM is unset (they are both used in d40_save_restore_registers). So would moving the definition into a #ifdef CONFIG_PM #endif block be better than __maybe_unused?
On Fri, Jul 12, 2019 at 9:17 PM 'Nick Desaulniers' via Clang Built Linux <clang-built-linux@googlegroups.com> wrote: > > On Fri, Jul 12, 2019 at 10:39 AM Nathan Chancellor > <natechancellor@gmail.com> wrote: > > > > On Fri, Jul 12, 2019 at 11:13:30AM +0200, Arnd Bergmann wrote: > > > clang-9 points out that there are two variables that depending on the > > > configuration may only be used in an ARRAY_SIZE() expression but not > > > referenced: > > > > > > drivers/dma/ste_dma40.c:145:12: error: variable 'd40_backup_regs' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > > > static u32 d40_backup_regs[] = { > > > ^ > > > drivers/dma/ste_dma40.c:214:12: error: variable 'd40_backup_regs_chan' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > > > static u32 d40_backup_regs_chan[] = { > > > > > > Mark these __maybe_unused to shut up the warning. > > > > > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > Thanks for the patch! > > > > > Might be worth mentioning that this warning will only appear when > > CONFIG_PM is unset (they are both used in d40_save_restore_registers). > > So would moving the definition into a > #ifdef CONFIG_PM > #endif > block be better than __maybe_unused? > That would not work here, since the driver still uses ARRAY_SIZE() on the variable. Even more #ifdefs could solve that as well, but I don't want to spend too much effort on this driver since it has almost no users. Arnd
On Fri, Jul 12, 2019 at 11:14 AM Arnd Bergmann <arnd@arndb.de> wrote: > clang-9 points out that there are two variables that depending on the > configuration may only be used in an ARRAY_SIZE() expression but not > referenced: > > drivers/dma/ste_dma40.c:145:12: error: variable 'd40_backup_regs' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > static u32 d40_backup_regs[] = { > ^ > drivers/dma/ste_dma40.c:214:12: error: variable 'd40_backup_regs_chan' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > static u32 d40_backup_regs_chan[] = { > > Mark these __maybe_unused to shut up the warning. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Seems like a reasonable fix: Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij
On 12-07-19, 11:13, Arnd Bergmann wrote: > clang-9 points out that there are two variables that depending on the > configuration may only be used in an ARRAY_SIZE() expression but not > referenced: > > drivers/dma/ste_dma40.c:145:12: error: variable 'd40_backup_regs' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > static u32 d40_backup_regs[] = { > ^ > drivers/dma/ste_dma40.c:214:12: error: variable 'd40_backup_regs_chan' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] > static u32 d40_backup_regs_chan[] = { > > Mark these __maybe_unused to shut up the warning. Applied, thanks
diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c index 89d710899010..de8bfd9a76e9 100644 --- a/drivers/dma/ste_dma40.c +++ b/drivers/dma/ste_dma40.c @@ -142,7 +142,7 @@ enum d40_events { * when the DMA hw is powered off. * TODO: Add save/restore of D40_DREG_GCC on dma40 v3 or later, if that works. */ -static u32 d40_backup_regs[] = { +static __maybe_unused u32 d40_backup_regs[] = { D40_DREG_LCPA, D40_DREG_LCLA, D40_DREG_PRMSE, @@ -211,7 +211,7 @@ static u32 d40_backup_regs_v4b[] = { #define BACKUP_REGS_SZ_V4B ARRAY_SIZE(d40_backup_regs_v4b) -static u32 d40_backup_regs_chan[] = { +static __maybe_unused u32 d40_backup_regs_chan[] = { D40_CHAN_REG_SSCFG, D40_CHAN_REG_SSELT, D40_CHAN_REG_SSPTR,
clang-9 points out that there are two variables that depending on the configuration may only be used in an ARRAY_SIZE() expression but not referenced: drivers/dma/ste_dma40.c:145:12: error: variable 'd40_backup_regs' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] static u32 d40_backup_regs[] = { ^ drivers/dma/ste_dma40.c:214:12: error: variable 'd40_backup_regs_chan' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] static u32 d40_backup_regs_chan[] = { Mark these __maybe_unused to shut up the warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/dma/ste_dma40.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)