lkml.org 
[lkml]   [2015]   [Feb]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] clk: Add tracepoints for hardware operations
On 02/02/15 08:00, Steven Rostedt wrote:
> On Fri, 30 Jan 2015 16:16:11 -0800
> Stephen Boyd <sboyd@codeaurora.org> wrote:
>
>> It's useful to have tracepoints around operations that change the
>> hardware state so that we can debug clock hardware performance
>> and operations. Four basic types of events are supported: on/off
>> events for enable, disable, prepare, unprepare that only record
>> an event and a clock name, rate changing events for
>> clk_set_{min_,max_}rate{_range}(), phase changing events for
>> clk_set_phase() and parent changing events for clk_set_parent().
>>
>> Cc: Steven Rostedt <rostedt@goodmis.org>
> I don't see anything wrong with the implementation of the tracepoints.
> Now whether or not they are useful is up to the clk maintainer to
> decide.
>
>> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
>> ---
>> drivers/clk/clk.c | 32 ++++++++
>> include/trace/events/clk.h | 198 +++++++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 230 insertions(+)
>> create mode 100644 include/trace/events/clk.h
>>
>
>
>> unlock_out:
>> @@ -861,9 +868,12 @@ static void clk_core_unprepare(struct clk_core *clk)
>>
>> WARN_ON(clk->enable_count > 0);
>>
>> + trace_clk_unprepare(clk);
>> +
>> if (clk->ops->unprepare)
>> clk->ops->unprepare(clk->hw);
>>
>> + trace_clk_unprepare_complete(clk);
>> clk_core_unprepare(clk->parent);
> I guess you do not care about the clk_core_unprepare time.

Function trace will handle that?

>
>> }
>>
>> @@ -901,6 +911,8 @@ static int clk_core_prepare(struct clk_core *clk)
>> if (ret)
>> return ret;
>>
>> + trace_clk_prepare(clk);
>> +
>> if (clk->ops->prepare) {
>> ret = clk->ops->prepare(clk->hw);
>> if (ret) {
>> @@ -908,6 +920,8 @@ static int clk_core_prepare(struct clk_core *clk)
>> return ret;
>> }
>> }
>> +
>> + trace_clk_prepare_complete(clk);
> I'm curious to why you do not put the tracepoint within the if
> statement, and only show the tracepoints if the clock prepare is
> actually called. Also, if you exit out with that return, will you tools
> be OK with seeing the clk_prepare but not the clk_prepare_complete?
>

Ah good point. I'll rework it so we always get the tracepoint around the
clk op.

--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project



\
 
 \ /
  Last update: 2015-02-02 21:21    [W:0.155 / U:0.704 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site