iwlwifi: device tracing

In order to have an easier way to debug issues, create
trace events (using the ftrace framework) that will
allow us to follow exactly what the driver is doing
with the device.

The text format isn't all that useful, but the binary
format can also be obtained easily via debugfs and
then analysed on the fly or offline with debugging
tools.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/Kconfig b/drivers/net/wireless/iwlwifi/Kconfig
index eb62c20..48d8f2c 100644
--- a/drivers/net/wireless/iwlwifi/Kconfig
+++ b/drivers/net/wireless/iwlwifi/Kconfig
@@ -49,6 +49,24 @@ config IWLWIFI_DEBUGFS
         ---help---
 	  Enable creation of debugfs files for the iwlwifi drivers.
 
+config IWLWIFI_DEVICE_TRACING
+	bool "iwlwifi device access tracing"
+	depends on IWLWIFI
+	depends on EVENT_TRACING
+	help
+	  Say Y here to trace all commands, including TX frames and IO
+	  accesses, sent to the device. If you say yes, iwlwifi will
+	  register with the ftrace framework for event tracing and dump
+	  all this information to the ringbuffer, you may need to
+	  increase the ringbuffer size. See the ftrace documentation
+	  for more information.
+
+	  When tracing is not enabled, this option still has some
+	  (though rather small) overhead.
+
+	  If unsure, say Y so we can help you better when problems
+	  occur.
+
 config IWLAGN
 	tristate "Intel Wireless WiFi Next Gen AGN (iwlagn)"
 	depends on IWLWIFI