Re: [PATCH v5] chrome/platform: cros_ec_proto: Add trace event to trace EC commands

[Steven Rostedt]

On Mon, 15 Apr 2019 14:57:04 -0600
Raul E Rangel <rrangel@xxxxxxxxxxxx> wrote:

> This is useful to see which EC commands are being executed and when.
> 
> To enable:
> 
>     echo 'cros_ec:*' >> /sys/kernel/debug/tracing/set_event

Note, you can accomplish the same thing with:

  echo 1 > /sys/kernel/debug/tracing/events/cros_ec/enable

That's the "new" way to do things. The set_event only hangs around for
historical (and compatibility) reasons.


> 
> Example:
> 
>     /* cros_ec_cmd: version: 0, command: EC_CMD_GET_VERSION */
>     /* cros_ec_cmd: version: 0, command: EC_CMD_GET_PROTOCOL_INFO */
>     /* cros_ec_cmd: version: 1, command: EC_CMD_GET_CMD_VERSIONS */
>     /* cros_ec_cmd: version: 1, command: EC_CMD_USB_PD_CONTROL */
> 
> Signed-off-by: Raul E Rangel <rrangel@xxxxxxxxxxxx>
> Reviewed-by: Ross Zwisler <zwisler@xxxxxxxxxx>

For the tracing side of things:

Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

-- Steve

> ---
> 
> Changes in v5:
> - Rebased on upstream/master. It turns out upstream/master is missing a
>   lot of changes to cros_ec_commands.h.
> - Replace SYM with SYMBOL in macro name.
> 
> Changes in v4:
> - Use the full command name so go to definition continues to work in my
> editor.
> 
> Changes in v3:
> - Use a macro to avoid duplicating the ec command names.
> 
> Changes in v2:
> - Changed comment style to match other cros_ec files.
> - Fixed commit tag.
> 
>  drivers/platform/chrome/Makefile        |   4 +-
>  drivers/platform/chrome/cros_ec_proto.c |   4 +
>  drivers/platform/chrome/cros_ec_trace.c | 121 ++++++++++++++++++++++++
>  drivers/platform/chrome/cros_ec_trace.h |  51 ++++++++++
>  4 files changed, 179 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/platform/chrome/cros_ec_trace.c
>  create mode 100644 drivers/platform/chrome/cros_ec_trace.h