DebugFS Support
===============

The QEP Linux Kernel Driver provides rich debugfs support. Along with configuration, status, and statistics, 
debug related information is also provided through the read-only interface. Debug information is provided for 
CMAC, QDMA, QEP and STM-N. The debugfs files are located at  /sys/kernel/debug/qep_dev/ in the host filesystem. 
For every QEP ethernet device detected, a filesystem tree is populated with directory name as its <BDF>

::

	# sudo tree /sys/kernel/debug/qep_dev/
	

The DebugFS filesystem tree is as shown below:

  .. image:: /images/debugfs.png
   :align: center

   
CMAC
----

This file contains a snapshot of error, status and statistics registers of CMAC IP. For details refer to CMAC user guide. 

Command:
::

	# cat /sys/kernel/debug/qep_dev/<BDF>/cmac
	
QDMA Info
---------
This file provides information about configuration mode of QDMA. 

Command:
::

	# cat /sys/kernel/debug/qep_dev/<BDF>/qdma_info
	
QDMA Register Dump
------------------
This file provides a snapshot of QDMA registers. For details of the registers, please refer to QDMA IP user guide UG302_

.. _UG302: https://www.xilinx.com/support/documentation/ip_documentation/qdma/v3_0/pg302-qdma.pdf

Command:
::

	# cat /sys/kernel/debug/qep_dev/<BDF>/qdma_regs
	
QEP Config
----------
This file provides information of QEP driver configuration modes.

Command:
::

	# cat /sys/kernel/debug/qep_dev/<BDF>/qep_config
	
Queues
------
This directory tree is dynamic and populates following files corresponding to C2H, H2C and CMPT queue, up to max number of configured queues.

* cntxt: Software and Hardware Context of queue

* desc: Raw descriptor queue

* info: Queue info

 
Command:
::

	# cat /sys/kernel/debug/qep_dev/<BDF>/queues/0/c2h/info
	
STM-N
-----
This file prints a snapshot of STM-N errors, drops, status and statistics. After every read, the underlying registers get cleared.  

Command:
::

	# cat /sys/kernel/debug/qep_dev/<BDF>/stmn