[PATCH v8 06/22] mfd: omap-usb-tll: introduce and use mode_needs_tll()

Russell King - ARM Linux linux at arm.linux.org.uk
Fri Jan 18 10:02:42 EST 2013


On Fri, Jan 18, 2013 at 02:17:09PM +0200, Roger Quadros wrote:
> +/* only PHY and UNUSED modes don't need TLL */
> +#define omap_usb_mode_needs_tll(x)	((x != OMAP_USBHS_PORT_MODE_UNUSED) &&\
> +					 (x != OMAP_EHCI_PORT_MODE_PHY))

Growl.

These parens do not make anything safer at all - they just obfuscate.  The
safe version of the above macro would have been:

#define omap_usb_mode_needs_tll(x)	((x) != OMAP_USBHS_PORT_MODE_UNUSED &&\
					 (x) != OMAP_EHCI_PORT_MODE_PHY)

If you're going to use a macro argument in an expression, it needs parens.
Simple expressions like a != b && c != d do _not_ need parens.




More information about the linux-arm-kernel mailing list