On Fri, Jul 12, 2019 at 9:17 PM 'Nick Desaulniers' via Clang Built
Linux [off-list ref] wrote:

On Fri, Jul 12, 2019 at 10:39 AM Nathan Chancellor
[off-list ref] wrote:

quoted

On Fri, Jul 12, 2019 at 11:13:30AM +0200, Arnd Bergmann wrote:

quoted

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!

quoted

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

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