Messages in this thread | | | Date | Fri, 18 Mar 2022 11:53:48 +0100 | From | Wolfram Sang <> | Subject | Re: [PATCH v2] i2c: add tracepoints for I2C slave events |
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Hi,
On Tue, Mar 08, 2022 at 08:33:33AM -0800, Jae Hyun Yoo wrote: > I2C slave events tracepoints can be enabled by: > > echo 1 > /sys/kernel/tracing/events/i2c_slave/enable > > and logs in /sys/kernel/tracing/trace will look like: > > ... i2c_slave: i2c-0 a=010 WR_REQ [] > ... i2c_slave: i2c-0 a=010 WR_RCV [02] > ... i2c_slave: i2c-0 a=010 WR_RCV [0c] > ... i2c_slave: i2c-0 a=010 STOP [] > ... i2c_slave: i2c-0 a=010 RD_REQ [04] > ... i2c_slave: i2c-0 a=010 RD_PRO [b4] > ... i2c_slave: i2c-0 a=010 STOP [] > > formatted as: > > i2c-<adapter-nr> > a=<addr> > <event> > [<data>] > > trace printings can be selected by adding a filter like: > > echo adapter_nr==1 >/sys/kernel/tracing/events/i2c_slave/filter > > Signed-off-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com>
Steven, are you happy with the tracepoint parts of this patch?
> + if (trace_i2c_slave_enabled() && !ret) > + trace_i2c_slave(client, event, val);
Why '!ret'? I think we should always print 'ret' in the trace as well. Backends are allowed to send errnos on WRITE_RECEIVED to NACK the reception of a byte. This is useful information, too, or?
Rest looks good to me.
Thanks,
Wolfram
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