Am Montag, den 27.07.2015, 13:12 +0200 schrieb Philipp Zabel: > Hi Hans, > > Am Sonntag, den 26.07.2015, 13:18 +0200 schrieb Hans Verkuil: > > Hi Philipp, > [...] > > > diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c > > > index 93b3154..b866a6b 100644 > > > --- a/drivers/media/v4l2-core/videobuf2-core.c > > > +++ b/drivers/media/v4l2-core/videobuf2-core.c > > > @@ -30,6 +30,8 @@ > > > #include <media/v4l2-common.h> > > > #include <media/videobuf2-core.h> > > > > > > > Shouldn't there be a #define CREATE_TRACE_POINTS added before the include? That's > > what is done in v4l2-ioctl.c as well. > > Documentation/trace/tracepoints.txt says > "if you use the header in multiple source files, > #define CREATE_TRACE_POINTS should appear only in one source file." > > > I updated my kernel on my laptop to the latest media master and without this line it > > gives me link errors: > > > > ERROR: "__tracepoint_vb2_qbuf" [drivers/media/v4l2-core/videobuf2-core.ko] undefined! > > ERROR: "__tracepoint_vb2_buf_done" [drivers/media/v4l2-core/videobuf2-core.ko] undefined! > > ERROR: "__tracepoint_vb2_buf_queue" [drivers/media/v4l2-core/videobuf2-core.ko] undefined! > > ERROR: "__tracepoint_vb2_dqbuf" [drivers/media/v4l2-core/videobuf2-core.ko] undefined! > > scripts/Makefile.modpost:90: recipe for target '__modpost' failed > > Since drivers/media/v4l2-core/v4l2-ioctl.c is built with the trace > points whenever CONFIG_VIDEO_V4L2 is enabled, the symbols will currently > end up in drivers/media/v4l2-core/v4l2-ioctl.o, but they are not > exported. > > > I'm not sure why I didn't see this anywhere else, but can you take a look at this? > > I didn't notice because I hadn't built kernels with VIDEO_V4L2 and > VIDEOBUF2_CORE as modules on x86. I'm not sure why I don't get these > errors on ARM, but I suppose this issue is a reason to split the vb2 > tracepoints out of include/trace/event/v4l2.h into their own header > anyway. The vb2 tracepoint implementation should reside in the > videobuf2-core module. I tried this yesterday and failed to figure out a satisfactory way to do it since the vb2 trace point macros reuse the v4l2 enum definitions and __print_symbolic/flags macros. The alternative would be to just export the vb2 trace points from videodev. regards Philipp -- 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
