The SMBUS tracepoints can be enabled thusly: echo 1 >/sys/kernel/debug/tracing/events/i2c/enable
and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace that look like: ... smbus_read: i2c-0 a=051 f=0000 c=fa BYTE_DATA ... smbus_reply: i2c-0 a=051 f=0000 c=fa BYTE_DATA l=1 [39] ... smbus_result: i2c-0 a=051 f=0000 c=fa BYTE_DATA rd res=0 formatted as: i2c-<adapter-nr> a=<addr> f=<flags> c=<command> <protocol-name> <rd|wr> res=<result> l=<data-len> [<data-block>] The adapters to be traced can be selected by something like: echo adapter_nr==1 >/sys/kernel/debug/tracing/events/i2c/filter Note that this shares the same filter and enablement as i2c. Signed-off-by: David Howells <dhowe...@redhat.com> Reviewed-by: Steven Rostedt <rost...@goodmis.org> --- drivers/i2c/i2c-core.c | 23 ++++- include/trace/events/i2c.h | 224 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 243 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index c8b97490461d..619910632d26 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -2552,6 +2552,14 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, int try; s32 res; + /* If enabled, the following two tracepoints are conditional on + * read_write and protocol. + */ + trace_smbus_write(adapter, addr, flags, read_write, + command, protocol, data); + trace_smbus_read(adapter, addr, flags, read_write, + command, protocol); + flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; if (adapter->algo->smbus_xfer) { @@ -2572,15 +2580,24 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, i2c_unlock_adapter(adapter); if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) - return res; + goto trace; /* * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't * implement native support for the SMBus operation. */ } - return i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, - command, protocol, data); + res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, + command, protocol, data); + +trace: + /* If enabled, the reply tracepoint is conditional on read_write. */ + trace_smbus_reply(adapter, addr, flags, read_write, + command, protocol, data); + trace_smbus_result(adapter, addr, flags, read_write, + command, protocol, res); + + return res; } EXPORT_SYMBOL(i2c_smbus_xfer); diff --git a/include/trace/events/i2c.h b/include/trace/events/i2c.h index 4800207269a2..fe17187df65d 100644 --- a/include/trace/events/i2c.h +++ b/include/trace/events/i2c.h @@ -1,4 +1,4 @@ -/* I2C message transfer tracepoints +/* I2C and SMBUS message transfer tracepoints * * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowe...@redhat.com) @@ -144,6 +144,228 @@ TRACE_EVENT_FN(i2c_result, i2c_transfer_trace_reg, i2c_transfer_trace_unreg); +/* + * i2c_smbus_xfer() write data or procedure call request + */ +TRACE_EVENT_CONDITION(smbus_write, + TP_PROTO(const struct i2c_adapter *adap, + u16 addr, unsigned short flags, + char read_write, u8 command, int protocol, + const union i2c_smbus_data *data), + TP_ARGS(adap, addr, flags, read_write, command, protocol, data), + TP_CONDITION(read_write == I2C_SMBUS_WRITE || + protocol == I2C_SMBUS_PROC_CALL || + protocol == I2C_SMBUS_BLOCK_PROC_CALL), + TP_STRUCT__entry( + __field(int, adapter_nr ) + __field(__u16, addr ) + __field(__u16, flags ) + __field(__u8, command ) + __field(__u8, len ) + __field(__u32, protocol ) + __array(__u8, buf, I2C_SMBUS_BLOCK_MAX + 2) ), + TP_fast_assign( + __entry->adapter_nr = adap->nr; + __entry->addr = addr; + __entry->flags = flags; + __entry->command = command; + __entry->protocol = protocol; + + switch (protocol) { + case I2C_SMBUS_BYTE_DATA: + __entry->len = 1; + goto copy; + case I2C_SMBUS_WORD_DATA: + case I2C_SMBUS_PROC_CALL: + __entry->len = 2; + goto copy; + case I2C_SMBUS_BLOCK_DATA: + case I2C_SMBUS_BLOCK_PROC_CALL: + case I2C_SMBUS_I2C_BLOCK_DATA: + __entry->len = data->block[0] + 1; + copy: + memcpy(__entry->buf, data->block, __entry->len); + break; + case I2C_SMBUS_QUICK: + case I2C_SMBUS_BYTE: + case I2C_SMBUS_I2C_BLOCK_BROKEN: + default: + __entry->len = 0; + } + ), + TP_printk("i2c-%d a=%03x f=%04x c=%x %s l=%u [%*phD]", + __entry->adapter_nr, + __entry->addr, + __entry->flags, + __entry->command, + __print_symbolic(__entry->protocol, + { I2C_SMBUS_QUICK, "QUICK" }, + { I2C_SMBUS_BYTE, "BYTE" }, + { I2C_SMBUS_BYTE_DATA, "BYTE_DATA" }, + { I2C_SMBUS_WORD_DATA, "WORD_DATA" }, + { I2C_SMBUS_PROC_CALL, "PROC_CALL" }, + { I2C_SMBUS_BLOCK_DATA, "BLOCK_DATA" }, + { I2C_SMBUS_I2C_BLOCK_BROKEN, "I2C_BLOCK_BROKEN" }, + { I2C_SMBUS_BLOCK_PROC_CALL, "BLOCK_PROC_CALL" }, + { I2C_SMBUS_I2C_BLOCK_DATA, "I2C_BLOCK_DATA" }), + __entry->len, + __entry->len, __entry->buf + )); + +/* + * i2c_smbus_xfer() read data request + */ +TRACE_EVENT_CONDITION(smbus_read, + TP_PROTO(const struct i2c_adapter *adap, + u16 addr, unsigned short flags, + char read_write, u8 command, int protocol), + TP_ARGS(adap, addr, flags, read_write, command, protocol), + TP_CONDITION(!(read_write == I2C_SMBUS_WRITE || + protocol == I2C_SMBUS_PROC_CALL || + protocol == I2C_SMBUS_BLOCK_PROC_CALL)), + TP_STRUCT__entry( + __field(int, adapter_nr ) + __field(__u16, flags ) + __field(__u16, addr ) + __field(__u8, command ) + __field(__u32, protocol ) + __array(__u8, buf, I2C_SMBUS_BLOCK_MAX + 2) ), + TP_fast_assign( + __entry->adapter_nr = adap->nr; + __entry->addr = addr; + __entry->flags = flags; + __entry->command = command; + __entry->protocol = protocol; + ), + TP_printk("i2c-%d a=%03x f=%04x c=%x %s", + __entry->adapter_nr, + __entry->addr, + __entry->flags, + __entry->command, + __print_symbolic(__entry->protocol, + { I2C_SMBUS_QUICK, "QUICK" }, + { I2C_SMBUS_BYTE, "BYTE" }, + { I2C_SMBUS_BYTE_DATA, "BYTE_DATA" }, + { I2C_SMBUS_WORD_DATA, "WORD_DATA" }, + { I2C_SMBUS_PROC_CALL, "PROC_CALL" }, + { I2C_SMBUS_BLOCK_DATA, "BLOCK_DATA" }, + { I2C_SMBUS_I2C_BLOCK_BROKEN, "I2C_BLOCK_BROKEN" }, + { I2C_SMBUS_BLOCK_PROC_CALL, "BLOCK_PROC_CALL" }, + { I2C_SMBUS_I2C_BLOCK_DATA, "I2C_BLOCK_DATA" }) + )); + +/* + * i2c_smbus_xfer() read data or procedure call reply + */ +TRACE_EVENT_CONDITION(smbus_reply, + TP_PROTO(const struct i2c_adapter *adap, + u16 addr, unsigned short flags, + char read_write, u8 command, int protocol, + const union i2c_smbus_data *data), + TP_ARGS(adap, addr, flags, read_write, command, protocol, data), + TP_CONDITION(read_write == I2C_SMBUS_READ), + TP_STRUCT__entry( + __field(int, adapter_nr ) + __field(__u16, addr ) + __field(__u16, flags ) + __field(__u8, command ) + __field(__u8, len ) + __field(__u32, protocol ) + __array(__u8, buf, I2C_SMBUS_BLOCK_MAX + 2) ), + TP_fast_assign( + __entry->adapter_nr = adap->nr; + __entry->addr = addr; + __entry->flags = flags; + __entry->command = command; + __entry->protocol = protocol; + + switch (protocol) { + case I2C_SMBUS_BYTE: + case I2C_SMBUS_BYTE_DATA: + __entry->len = 1; + goto copy; + case I2C_SMBUS_WORD_DATA: + case I2C_SMBUS_PROC_CALL: + __entry->len = 2; + goto copy; + case I2C_SMBUS_BLOCK_DATA: + case I2C_SMBUS_BLOCK_PROC_CALL: + case I2C_SMBUS_I2C_BLOCK_DATA: + __entry->len = data->block[0] + 1; + copy: + memcpy(__entry->buf, data->block, __entry->len); + break; + case I2C_SMBUS_QUICK: + case I2C_SMBUS_I2C_BLOCK_BROKEN: + default: + __entry->len = 0; + } + ), + TP_printk("i2c-%d a=%03x f=%04x c=%x %s l=%u [%*phD]", + __entry->adapter_nr, + __entry->addr, + __entry->flags, + __entry->command, + __print_symbolic(__entry->protocol, + { I2C_SMBUS_QUICK, "QUICK" }, + { I2C_SMBUS_BYTE, "BYTE" }, + { I2C_SMBUS_BYTE_DATA, "BYTE_DATA" }, + { I2C_SMBUS_WORD_DATA, "WORD_DATA" }, + { I2C_SMBUS_PROC_CALL, "PROC_CALL" }, + { I2C_SMBUS_BLOCK_DATA, "BLOCK_DATA" }, + { I2C_SMBUS_I2C_BLOCK_BROKEN, "I2C_BLOCK_BROKEN" }, + { I2C_SMBUS_BLOCK_PROC_CALL, "BLOCK_PROC_CALL" }, + { I2C_SMBUS_I2C_BLOCK_DATA, "I2C_BLOCK_DATA" }), + __entry->len, + __entry->len, __entry->buf + )); + +/* + * i2c_smbus_xfer() result + */ +TRACE_EVENT(smbus_result, + TP_PROTO(const struct i2c_adapter *adap, + u16 addr, unsigned short flags, + char read_write, u8 command, int protocol, + int res), + TP_ARGS(adap, addr, flags, read_write, command, protocol, res), + TP_STRUCT__entry( + __field(int, adapter_nr ) + __field(__u16, addr ) + __field(__u16, flags ) + __field(__u8, read_write ) + __field(__u8, command ) + __field(__s16, res ) + __field(__u32, protocol ) + ), + TP_fast_assign( + __entry->adapter_nr = adap->nr; + __entry->addr = addr; + __entry->flags = flags; + __entry->read_write = read_write; + __entry->command = command; + __entry->protocol = protocol; + __entry->res = res; + ), + TP_printk("i2c-%d a=%03x f=%04x c=%x %s %s res=%d", + __entry->adapter_nr, + __entry->addr, + __entry->flags, + __entry->command, + __print_symbolic(__entry->protocol, + { I2C_SMBUS_QUICK, "QUICK" }, + { I2C_SMBUS_BYTE, "BYTE" }, + { I2C_SMBUS_BYTE_DATA, "BYTE_DATA" }, + { I2C_SMBUS_WORD_DATA, "WORD_DATA" }, + { I2C_SMBUS_PROC_CALL, "PROC_CALL" }, + { I2C_SMBUS_BLOCK_DATA, "BLOCK_DATA" }, + { I2C_SMBUS_I2C_BLOCK_BROKEN, "I2C_BLOCK_BROKEN" }, + { I2C_SMBUS_BLOCK_PROC_CALL, "BLOCK_PROC_CALL" }, + { I2C_SMBUS_I2C_BLOCK_DATA, "I2C_BLOCK_DATA" }), + __entry->read_write == I2C_SMBUS_WRITE ? "wr" : "rd", + __entry->res + )); + #endif /* _TRACE_I2C_H */ /* This part must be outside protection */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/