On Thu, Mar 17, 2016 at 07:40:59AM +0100, Heiner Kallweit wrote: > Am 16.03.2016 um 23:28 schrieb Sean Young: > > On Wed, Mar 16, 2016 at 10:18:38PM +0100, Heiner Kallweit wrote: > >> + u8 pulse:1; > >> + u8 reset:1; > >> + u8 timeout:1; > >> + u8 carrier_report:1; > > > > Why are you changing the type of the bitfields? > > > I did this to make sure that the compiler uses one byte for > the bit field. When testing gcc also used just one byte when > keeping the original "unsigned" type for the bit field members. > Therefore it wouldn't be strictly neeeded. > > But I'm not sure whether it's guaranteed that the compiler packs a > bit field to the smallest possible data type and we can rely on it. > AFAIK C99 is a little more specific about this implementation detail of > bit fields but C89/C90 is used for kernel compilation. It might be worth reading about structure packing rules rather than guessing. Sean -- 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
