On Sun, 5 Jul 2009, Jean Delvare wrote: > Hi Trent, > > On Sun, 5 Jul 2009 01:13:14 -0700 (PDT), Trent Piepho wrote: > > On Fri, 3 Jul 2009, Jean Delvare wrote: > > > Kernels 2.6.22 to 2.6.24 (inclusive) need some compatibility quirks > > > for the hrtimer API. For older kernels, some required functions were > > > not exported so there's nothing we can do. This means that drivers > > > using the hrtimer infrastructure will no longer work for kernels older > > > than 2.6.22. > > > > > > Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx> > > > --- > > > v4l/compat.h | 18 ++++++++++++++++++ > > > 1 file changed, 18 insertions(+) > > > > > > --- a/v4l/compat.h > > > +++ b/v4l/compat.h > > > @@ -480,4 +480,22 @@ static inline unsigned long v4l_compat_f > > > } > > > #endif > > > > > > +/* > > > + * Compatibility code for hrtimer API > > > + * This will make hrtimer usable for kernels 2.6.22 and later. > > > + * For earlier kernels, not all required functions are exported > > > + * so there's nothing we can do. > > > + */ > > > + > > > +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 25) && \ > > > + LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22) > > > +#include <linux/hrtimer.h> > > > > Instead of including hrtimer.h from compat.h it's better if you check if it > > has already been included and only enable the compat code in that case. > > That way hrtimer doesn't get included for files that don't need it and > > might define something that conflicts with something from hrtimer. And it > > prevents someone from forgetting to include hrtimer when they needed it, > > but having the error masked because compat.h is doing it for them. > > I see. But this will only work if compat.h is included after all > headers. If it always the case? I see for example that cx88-input > includes <media/ir-common.h> after "compat.h". Headers that come from the kernel come before compat.h and headers that come from the v4l-dvb tree come after compat.h. -- 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
