Re: [PATCH] visl: use canonical ftrace path

[Hans Verkuil]

On 03/10/2023 23:41, Steven Rostedt wrote:
> 
> Could this go through the linux-media tree, or if you give it an Ack, I'll
> take it through the tracing tree.

I prefer to take this through the media subsystem. Ross, can you post this
patch again, this time including linux-media@xxxxxxxxxxxxxxx?

The patch looks fine, so I'll pick it up.

Regards,

	Hans

> 
> -- Steve
> 
> 
> On Tue, 29 Aug 2023 14:46:01 -0600
> Ross Zwisler <zwisler@xxxxxxxxxx> wrote:
> 
>> From: Ross Zwisler <zwisler@xxxxxxxxxx>
>>
>> The canonical location for the tracefs filesystem is at /sys/kernel/tracing.
>>
>> But, from Documentation/trace/ftrace.rst:
>>
>>   Before 4.1, all ftrace tracing control files were within the debugfs
>>   file system, which is typically located at /sys/kernel/debug/tracing.
>>   For backward compatibility, when mounting the debugfs file system,
>>   the tracefs file system will be automatically mounted at:
>>
>>   /sys/kernel/debug/tracing
>>
>> Update the visl decoder driver documentation to use this tracefs path.
>>
>> Signed-off-by: Ross Zwisler <zwisler@xxxxxxxxxx>
>> ---
>>  Documentation/admin-guide/media/visl.rst | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/Documentation/admin-guide/media/visl.rst b/Documentation/admin-guide/media/visl.rst
>> index 7d2dc78341c9..4328c6c72d30 100644
>> --- a/Documentation/admin-guide/media/visl.rst
>> +++ b/Documentation/admin-guide/media/visl.rst
>> @@ -78,7 +78,7 @@ The trace events are defined on a per-codec basis, e.g.:
>>  
>>  .. code-block:: bash
>>  
>> -        $ ls /sys/kernel/debug/tracing/events/ | grep visl
>> +        $ ls /sys/kernel/tracing/events/ | grep visl
>>          visl_fwht_controls
>>          visl_h264_controls
>>          visl_hevc_controls
>> @@ -90,13 +90,13 @@ For example, in order to dump HEVC SPS data:
>>  
>>  .. code-block:: bash
>>  
>> -        $ echo 1 >  /sys/kernel/debug/tracing/events/visl_hevc_controls/v4l2_ctrl_hevc_sps/enable
>> +        $ echo 1 >  /sys/kernel/tracing/events/visl_hevc_controls/v4l2_ctrl_hevc_sps/enable
>>  
>>  The SPS data will be dumped to the trace buffer, i.e.:
>>  
>>  .. code-block:: bash
>>  
>> -        $ cat /sys/kernel/debug/tracing/trace
>> +        $ cat /sys/kernel/tracing/trace
>>          video_parameter_set_id 0
>>          seq_parameter_set_id 0
>>          pic_width_in_luma_samples 1920
>