On Wed, 2010-11-17 at 10:55 +0100, Arnd Bergmann wrote:
> On Tuesday 16 November 2010, Joe Perches wrote:
> > static inline u32 MCDE_channel_path(u32 chnl, u32 fifo, u32 type, u32 ifc, u32 link)
> > {
> > return ((chnl << 16) |
> > (fifo << 12) |
> > (type << 8) |
> > (ifc << 4) |
> > (link << 0));
> > }
> >
> > #define SET_ENUM_MCDE_CHNLPATH(chnl, fifo, var, type, ifc, link) \
> > MCDE_CHNLPATH_CHNL##chnl##_FIFO##fifo##_##var = \
> > MCDE_channel_path(MCDE_CHNL_##chnl, \
> > MCDE_FIFO_##fifo, \
> > MCDE_PORTTYPE_##type, \
> > ifc, \
> > link)
> >
> > enum mcde_chnl_path {
> > /* Channel A */
> > SET_ENUM_MCDE_CHNLPATH(A, A, DPI_0, DPI, 0, 0),
> > SET_ENUM_MCDE_CHNLPATH(A, A, DSI_IFC0_0, DSI, 0, 0),
> > SET_ENUM_MCDE_CHNLPATH(A, A, DSI_IFC0_1, DSI, 0, 1),
>
> While more readable, this has two significant problems:
>
> * You cannot use the result of an inline function in an enum definition
> * It hides the name of the identifier, making it impossible to use grep
> or ctags to find the definition when you only know the name
True, though I would avoid that problem by using a get function/macro
and not use an enum at all.
There are just 4 items of interest here. chan, fifo, #1, #2.
Encoding those in the variable name is a bit of a visual chase and
a bit mind numbing to read I think.
> The easiest way is probably to get rid of the macros entirely here
> and just define the values as hex, with a comment exmplaining what the
> digits mean.
That'd be fine too.
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
