Re: [for-next][PATCH 19/21] v4l: Export enums used by tracepoints to user space

From: Mauro Carvalho Chehab
Date: Wed Apr 08 2015 - 10:43:17 EST


Em Wed, 08 Apr 2015 09:48:23 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> escreveu:

> From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>
>
> Enums used by tracepoints for __print_symbolic() are shown in the
> tracepoint format files with just their names and not their values.
> This makes it difficult for user space tools to know how to convert the
> binary data into their string representations.
>
> By adding the use of TRACE_DEFINE_ENUM(), the enum names will be mapped
> to their values and shown in the tracing file system to let tools
> convert the data as necessary.
>
> Link: http://lkml.kernel.org/r/20150403013802.220157513@xxxxxxxxxxx
>
> Cc: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>

Acked-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>

> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> ---
> include/trace/events/v4l2.h | 75 ++++++++++++++++++++++++++++++---------------
> 1 file changed, 50 insertions(+), 25 deletions(-)
>
> diff --git a/include/trace/events/v4l2.h b/include/trace/events/v4l2.h
> index b9bb1f204693..20112170ff11 100644
> --- a/include/trace/events/v4l2.h
> +++ b/include/trace/events/v4l2.h
> @@ -6,33 +6,58 @@
>
> #include <linux/tracepoint.h>
>
> -#define show_type(type) \
> - __print_symbolic(type, \
> - { V4L2_BUF_TYPE_VIDEO_CAPTURE, "VIDEO_CAPTURE" }, \
> - { V4L2_BUF_TYPE_VIDEO_OUTPUT, "VIDEO_OUTPUT" }, \
> - { V4L2_BUF_TYPE_VIDEO_OVERLAY, "VIDEO_OVERLAY" }, \
> - { V4L2_BUF_TYPE_VBI_CAPTURE, "VBI_CAPTURE" }, \
> - { V4L2_BUF_TYPE_VBI_OUTPUT, "VBI_OUTPUT" }, \
> - { V4L2_BUF_TYPE_SLICED_VBI_CAPTURE, "SLICED_VBI_CAPTURE" }, \
> - { V4L2_BUF_TYPE_SLICED_VBI_OUTPUT, "SLICED_VBI_OUTPUT" }, \
> - { V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY, "VIDEO_OUTPUT_OVERLAY" },\
> - { V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE, "VIDEO_CAPTURE_MPLANE" },\
> - { V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE, "VIDEO_OUTPUT_MPLANE" }, \
> - { V4L2_BUF_TYPE_SDR_CAPTURE, "SDR_CAPTURE" }, \
> - { V4L2_BUF_TYPE_PRIVATE, "PRIVATE" })
> +/* Enums require being exported to userspace, for user tool parsing */
> +#undef EM
> +#undef EMe
> +#define EM(a, b) TRACE_DEFINE_ENUM(a);
> +#define EMe(a, b) TRACE_DEFINE_ENUM(a);
> +
> +#define show_type(type) \
> + __print_symbolic(type, SHOW_TYPE)
> +
> +#define SHOW_TYPE \
> + EM( V4L2_BUF_TYPE_VIDEO_CAPTURE, "VIDEO_CAPTURE" ) \
> + EM( V4L2_BUF_TYPE_VIDEO_OUTPUT, "VIDEO_OUTPUT" ) \
> + EM( V4L2_BUF_TYPE_VIDEO_OVERLAY, "VIDEO_OVERLAY" ) \
> + EM( V4L2_BUF_TYPE_VBI_CAPTURE, "VBI_CAPTURE" ) \
> + EM( V4L2_BUF_TYPE_VBI_OUTPUT, "VBI_OUTPUT" ) \
> + EM( V4L2_BUF_TYPE_SLICED_VBI_CAPTURE, "SLICED_VBI_CAPTURE" ) \
> + EM( V4L2_BUF_TYPE_SLICED_VBI_OUTPUT, "SLICED_VBI_OUTPUT" ) \
> + EM( V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY, "VIDEO_OUTPUT_OVERLAY" ) \
> + EM( V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE, "VIDEO_CAPTURE_MPLANE" ) \
> + EM( V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE, "VIDEO_OUTPUT_MPLANE" ) \
> + EM( V4L2_BUF_TYPE_SDR_CAPTURE, "SDR_CAPTURE" ) \
> + EMe(V4L2_BUF_TYPE_PRIVATE, "PRIVATE" )
> +
> +SHOW_TYPE
>
> #define show_field(field) \
> - __print_symbolic(field, \
> - { V4L2_FIELD_ANY, "ANY" }, \
> - { V4L2_FIELD_NONE, "NONE" }, \
> - { V4L2_FIELD_TOP, "TOP" }, \
> - { V4L2_FIELD_BOTTOM, "BOTTOM" }, \
> - { V4L2_FIELD_INTERLACED, "INTERLACED" }, \
> - { V4L2_FIELD_SEQ_TB, "SEQ_TB" }, \
> - { V4L2_FIELD_SEQ_BT, "SEQ_BT" }, \
> - { V4L2_FIELD_ALTERNATE, "ALTERNATE" }, \
> - { V4L2_FIELD_INTERLACED_TB, "INTERLACED_TB" }, \
> - { V4L2_FIELD_INTERLACED_BT, "INTERLACED_BT" })
> + __print_symbolic(field, SHOW_FIELD)
> +
> +#define SHOW_FIELD \
> + EM( V4L2_FIELD_ANY, "ANY" ) \
> + EM( V4L2_FIELD_NONE, "NONE" ) \
> + EM( V4L2_FIELD_TOP, "TOP" ) \
> + EM( V4L2_FIELD_BOTTOM, "BOTTOM" ) \
> + EM( V4L2_FIELD_INTERLACED, "INTERLACED" ) \
> + EM( V4L2_FIELD_SEQ_TB, "SEQ_TB" ) \
> + EM( V4L2_FIELD_SEQ_BT, "SEQ_BT" ) \
> + EM( V4L2_FIELD_ALTERNATE, "ALTERNATE" ) \
> + EM( V4L2_FIELD_INTERLACED_TB, "INTERLACED_TB" ) \
> + EMe( V4L2_FIELD_INTERLACED_BT, "INTERLACED_BT" )
> +
> +SHOW_FIELD
> +
> +/*
> + * Now redefine the EM() and EMe() macros to map the enums to the strings
> + * that will be printed in the output.
> + */
> +#undef EM
> +#undef EMe
> +#define EM(a, b) {a, b},
> +#define EMe(a, b) {a, b}
> +
> +/* V4L2_TC_TYPE_* are macros, not defines, they do not need processing */
>
> #define show_timecode_type(type) \
> __print_symbolic(type, \
--
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