[PATCH] [media] v4l2: move tracepoint generation into separate file

[PATCH] [media] v4l2: move tracepoint generation into separate file

[Philipp Zabel]

To compile videobuf2-core as a module, the vb2_* tracepoints must be
exported from the videodev module. Instead of exporting vb2 tracepoint
symbols from v4l2-ioctl.c, move the tracepoint generation into a separate
file. This patch fixes the following build error in the modpost stage,
introduced by 2091f5181c66 ("[media] videobuf2: add trace events"):

    ERROR: "__tracepoint_vb2_buf_done" undefined!
    ERROR: "__tracepoint_vb2_dqbuf" undefined!
    ERROR: "__tracepoint_vb2_qbuf" undefined!
    ERROR: "__tracepoint_vb2_buf_queue" undefined!

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 drivers/media/v4l2-core/Makefile     |  3 +++
 drivers/media/v4l2-core/v4l2-ioctl.c |  1 -
 drivers/media/v4l2-core/v4l2-trace.c | 11 +++++++++++
 3 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 drivers/media/v4l2-core/v4l2-trace.c

diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile
index dc3de00..d1dd440 100644
--- a/drivers/media/v4l2-core/Makefile
+++ b/drivers/media/v4l2-core/Makefile
@@ -13,6 +13,9 @@ endif
 ifeq ($(CONFIG_OF),y)
   videodev-objs += v4l2-of.o
 endif
+ifeq ($(CONFIG_TRACEPOINTS),y)
+  videodev-objs += v4l2-trace.o
+endif
 
 obj-$(CONFIG_VIDEO_V4L2) += videodev.o
 obj-$(CONFIG_VIDEO_V4L2) += v4l2-common.o
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 85de455..038d8c0 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -28,7 +28,6 @@
 #include <media/v4l2-device.h>
 #include <media/videobuf2-core.h>
 
-#define CREATE_TRACE_POINTS
 #include <trace/events/v4l2.h>
 
 /* Zero out the end of the struct pointed to by p.  Everything after, but
diff --git a/drivers/media/v4l2-core/v4l2-trace.c b/drivers/media/v4l2-core/v4l2-trace.c
new file mode 100644
index 0000000..ae10b02
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-trace.c
@@ -0,0 +1,11 @@
+#include <media/v4l2-common.h>
+#include <media/v4l2-fh.h>
+#include <media/videobuf2-core.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/v4l2.h>
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(vb2_buf_done);
+EXPORT_TRACEPOINT_SYMBOL_GPL(vb2_buf_queue);
+EXPORT_TRACEPOINT_SYMBOL_GPL(vb2_dqbuf);
+EXPORT_TRACEPOINT_SYMBOL_GPL(vb2_qbuf);
-- 
2.4.6

Re: [PATCH] [media] v4l2: move tracepoint generation into separate file

[Steven Rostedt]

On Thu,  6 Aug 2015 14:38:02 +0200
Philipp Zabel <p.zabel@pengutronix.de> wrote:

> To compile videobuf2-core as a module, the vb2_* tracepoints must be
> exported from the videodev module. Instead of exporting vb2 tracepoint
> symbols from v4l2-ioctl.c, move the tracepoint generation into a separate
> file. This patch fixes the following build error in the modpost stage,
> introduced by 2091f5181c66 ("[media] videobuf2: add trace events"):
> 
>     ERROR: "__tracepoint_vb2_buf_done" undefined!
>     ERROR: "__tracepoint_vb2_dqbuf" undefined!
>     ERROR: "__tracepoint_vb2_qbuf" undefined!
>     ERROR: "__tracepoint_vb2_buf_queue" undefined!
> 

Suggested-by: Steven Rostedt <rostedt@goodmis.org>

 ;-)

-- Steve

> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> ---

Re: [PATCH] [media] v4l2: move tracepoint generation into separate file

[Philipp Zabel]

Am Donnerstag, den 06.08.2015, 09:23 -0400 schrieb Steven Rostedt:
> On Thu,  6 Aug 2015 14:38:02 +0200
> Philipp Zabel <p.zabel@pengutronix.de> wrote:
> 
> > To compile videobuf2-core as a module, the vb2_* tracepoints must be
> > exported from the videodev module. Instead of exporting vb2 tracepoint
> > symbols from v4l2-ioctl.c, move the tracepoint generation into a separate
> > file. This patch fixes the following build error in the modpost stage,
> > introduced by 2091f5181c66 ("[media] videobuf2: add trace events"):
> > 
> >     ERROR: "__tracepoint_vb2_buf_done" undefined!
> >     ERROR: "__tracepoint_vb2_dqbuf" undefined!
> >     ERROR: "__tracepoint_vb2_qbuf" undefined!
> >     ERROR: "__tracepoint_vb2_buf_queue" undefined!
> > 
> 
> Suggested-by: Steven Rostedt <rostedt@goodmis.org>
> 
>  ;-)

Indeed, thank you.

regards
Philipp