Re: [PATCH] smc91x: avoid self-comparison warning

From: David Miller
Date: Mon Mar 14 2016 - 19:37:26 EST

From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Mon, 14 Mar 2016 23:45:12 +0100

> The smc91x driver defines a macro that compares its argument to
> itself, apparently to get a true result while using its argument
> to avoid a warning about unused local variables.
> Unfortunately, this triggers a warning with gcc-6, as the comparison
> is obviously useless:
> drivers/net/ethernet/smsc/smc91x.c: In function 'smc_hardware_send_pkt':
> drivers/net/ethernet/smsc/smc91x.c:563:14: error: self-comparison always evaluates to true [-Werror=tautological-compare]
> if (!smc_special_trylock(&lp->lock, flags)) {
> This replaces the macro with another one that behaves similarly,
> with a cast to (void) to ensure the argument is used, and using
> a literal 'true' as its value.
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Applied, thanks.