Add basic trace events for i2c_transfer() and i2c_smbus_xfer() so we can observe the I2C/SMBus activity without filling up the dmesg ring buffer.
Signed-off-by: Dimitris Papastamos <[email protected]> --- drivers/i2c/i2c-core.c | 8 ++++- include/trace/events/i2c.h | 70 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+), 1 deletions(-) create mode 100644 include/trace/events/i2c.h diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index f0bd5bc..848f0fc 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -42,6 +42,8 @@ #include "i2c-core.h" +#define CREATE_TRACE_POINTS +#include <trace/events/i2c.h> /* core_lock protects i2c_adapter_idr, and guarantees that device detection, deletion of detected devices, and attach_adapter @@ -1289,7 +1291,7 @@ module_exit(i2c_exit); int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { unsigned long orig_jiffies; - int ret, try; + int ret, try, i; /* REVISIT the fault reporting model here is weak: * @@ -1330,6 +1332,8 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) /* Retry automatically on arbitration loss */ orig_jiffies = jiffies; for (ret = 0, try = 0; try <= adap->retries; try++) { + for (i = 0; i < num; i++) + trace_i2c_transfer(adap->name, &msgs[i]); ret = adap->algo->master_xfer(adap, msgs, num); if (ret != -EAGAIN) break; @@ -2089,6 +2093,8 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, /* Retry automatically on arbitration loss */ orig_jiffies = jiffies; for (res = 0, try = 0; try <= adapter->retries; try++) { + trace_i2c_smbus_xfer(adapter->name, addr, flags, + read_write, command, protocol); res = adapter->algo->smbus_xfer(adapter, addr, flags, read_write, command, protocol, data); diff --git a/include/trace/events/i2c.h b/include/trace/events/i2c.h new file mode 100644 index 0000000..2c1fb9b --- /dev/null +++ b/include/trace/events/i2c.h @@ -0,0 +1,70 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM i2c + +#if !defined(_TRACE_I2C_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_I2C_H + +#include <linux/ktime.h> +#include <linux/tracepoint.h> + +struct i2c_msg; + +TRACE_EVENT(i2c_transfer, + + TP_PROTO(const char *name, struct i2c_msg *msg), + + TP_ARGS(name, msg), + + TP_STRUCT__entry( + __string( name, name ) + __field( u16, addr ) + __field( u16, len ) + __field( u16, flags ) + ), + + TP_fast_assign( + __assign_str(name, name); + __entry->addr = msg->addr; + __entry->len = msg->len; + __entry->flags = msg->flags; + ), + + TP_printk("name=%s addr=%#x len=%#x flags=%#x", __get_str(name), + (u16)__entry->addr, (u16)__entry->len, (u16)__entry->flags) +); + +TRACE_EVENT(i2c_smbus_xfer, + + TP_PROTO(const char *name, u16 addr, unsigned short flags, + char read_write, u8 command, int protocol), + + TP_ARGS(name, addr, flags, read_write, command, protocol), + + TP_STRUCT__entry( + __string( name, name ) + __field( u16, addr ) + __field( unsigned short, flags ) + __field( char, read_write ) + __field( u8, command ) + __field( int, protocol ) + ), + + TP_fast_assign( + __assign_str(name, name); + __entry->addr = addr; + __entry->flags = flags; + __entry->read_write = read_write; + __entry->command = command; + __entry->protocol = protocol; + ), + + TP_printk("name=%s addr=%#x flags=%#x read_write=%#x command=%#x protocol=%#x", + __get_str(name), (u16)__entry->addr, + (unsigned short)__entry->flags, (char)__entry->read_write, + (u8)__entry->command, (int)__entry->protocol) +); + +#endif /* _TRACE_I2C_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> -- 1.7.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
