From: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
To: David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: wolfram-z923LK4zBo2bacvFa/9K2g@public.gmane.org,
khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH 1/2] i2c: Add message transfer tracepoints for I2C [ver #2]
Date: Thu, 13 Mar 2014 22:15:32 +0100 [thread overview]
Message-ID: <20140313211532.GA2696@katana> (raw)
In-Reply-To: <20140306133559.29345.61422.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
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On Thu, Mar 06, 2014 at 01:35:59PM +0000, David Howells wrote:
> Add tracepoints into the I2C message transfer function to retrieve the message
> sent or received. The following config options must be turned on to make use
> of the facility:
>
> CONFIG_FTRACE
> CONFIG_ENABLE_DEFAULT_TRACERS
>
> The I2C tracepoint can be enabled thusly:
>
> echo 1 >/sys/kernel/debug/tracing/events/i2c/i2c_transfer/enable
>
> and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace
> that look like:
>
> ... i2c_write: i2c-5 #0 a=044 f=0000 l=2 [02-14]
> ... i2c_read: i2c-5 #1 a=044 f=0001 l=4
> ... i2c_reply: i2c-5 #1 a=044 f=0001 l=4 [33-00-00-00]
> ... i2c_result: i2c-5 n=2 ret=2
>
> formatted as:
>
> i2c-<adapter-nr>
> #<message-array-index>
> a=<addr>
> f=<flags>
> l=<datalen>
> n=<message-array-size>
> ret=<result>
> [<data>]
>
> The operation is done between the i2c_write/i2c_read lines and the i2c_reply
> and i2c_result lines so that if the hardware hangs, the trace buffer can be
> consulted to determine the problematic operation.
>
> The adapters to be traced can be selected by something like:
>
> echo adapter_nr==1 >/sys/kernel/debug/tracing/events/i2c/filter
>
> These changes are based on code from Steven Rostedt.
>
> Signed-off-by: Steven Rostedt <rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org>
> Signed-off-by: David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> Reviewed-by: Steven Rostedt <rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org>
Applied to for-next, thanks!
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WARNING: multiple messages have this Message-ID (diff)
From: Wolfram Sang <wsa@the-dreams.de>
To: David Howells <dhowells@redhat.com>
Cc: wolfram@the-dreams.de, khali@linux-fr.org,
linux-i2c@vger.kernel.org, rostedt@goodmis.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] i2c: Add message transfer tracepoints for I2C [ver #2]
Date: Thu, 13 Mar 2014 22:15:32 +0100 [thread overview]
Message-ID: <20140313211532.GA2696@katana> (raw)
In-Reply-To: <20140306133559.29345.61422.stgit@warthog.procyon.org.uk>
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On Thu, Mar 06, 2014 at 01:35:59PM +0000, David Howells wrote:
> Add tracepoints into the I2C message transfer function to retrieve the message
> sent or received. The following config options must be turned on to make use
> of the facility:
>
> CONFIG_FTRACE
> CONFIG_ENABLE_DEFAULT_TRACERS
>
> The I2C tracepoint can be enabled thusly:
>
> echo 1 >/sys/kernel/debug/tracing/events/i2c/i2c_transfer/enable
>
> and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace
> that look like:
>
> ... i2c_write: i2c-5 #0 a=044 f=0000 l=2 [02-14]
> ... i2c_read: i2c-5 #1 a=044 f=0001 l=4
> ... i2c_reply: i2c-5 #1 a=044 f=0001 l=4 [33-00-00-00]
> ... i2c_result: i2c-5 n=2 ret=2
>
> formatted as:
>
> i2c-<adapter-nr>
> #<message-array-index>
> a=<addr>
> f=<flags>
> l=<datalen>
> n=<message-array-size>
> ret=<result>
> [<data>]
>
> The operation is done between the i2c_write/i2c_read lines and the i2c_reply
> and i2c_result lines so that if the hardware hangs, the trace buffer can be
> consulted to determine the problematic operation.
>
> The adapters to be traced can be selected by something like:
>
> echo adapter_nr==1 >/sys/kernel/debug/tracing/events/i2c/filter
>
> These changes are based on code from Steven Rostedt.
>
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
> Signed-off-by: David Howells <dhowells@redhat.com>
> Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Applied to for-next, thanks!
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next prev parent reply other threads:[~2014-03-13 21:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-06 13:35 [PATCH 1/2] i2c: Add message transfer tracepoints for I2C [ver #2] David Howells
2014-03-06 13:36 ` [PATCH 2/2] i2c: Add message transfer tracepoints for SMBUS " David Howells
[not found] ` <20140306133606.29345.97103.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2014-03-13 21:15 ` Wolfram Sang
2014-03-13 21:15 ` Wolfram Sang
[not found] ` <20140306133559.29345.61422.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2014-03-13 21:15 ` Wolfram Sang [this message]
2014-03-13 21:15 ` [PATCH 1/2] i2c: Add message transfer tracepoints for I2C " Wolfram Sang
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