Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 711 insertions, 0 deletions

diff --git a/Documentation/driver-api/usb/dwc3.rst b/Documentation/driver-api/usb/dwc3.rst
new file mode 100644
index 000000000..e3d6a6209
--- /dev/null
+++ b/Documentation/driver-api/usb/dwc3.rst
@@ -0,0 +1,711 @@
+===============================================================
+Synopsys DesignWare Core SuperSpeed USB 3.0 Controller
+===============================================================
+
+:Author: Felipe Balbi <felipe.balbi@linux.intel.com>
+:Date: April 2017
+
+Introduction
+============
+
+The *Synopsys DesignWare Core SuperSpeed USB 3.0 Controller*
+(hereinafter referred to as *DWC3*) is a USB SuperSpeed compliant
+controller which can be configured in one of 4 ways:
+
+	1. Peripheral-only configuration
+	2. Host-only configuration
+	3. Dual-Role configuration
+	4. Hub configuration
+
+Linux currently supports several versions of this controller. In all
+likelihood, the version in your SoC is already supported. At the time
+of this writing, known tested versions range from 2.02a to 3.10a. As a
+rule of thumb, anything above 2.02a should work reliably well.
+
+Currently, we have many known users for this driver. In alphabetical
+order:
+
+	1. Cavium
+	2. Intel Corporation
+	3. Qualcomm
+	4. Rockchip
+	5. ST
+	6. Samsung
+	7. Texas Instruments
+	8. Xilinx
+
+Summary of Features
+======================
+
+For details about features supported by your version of DWC3, consult
+your IP team and/or *Synopsys DesignWare Core SuperSpeed USB 3.0
+Controller Databook*. Following is a list of features supported by the
+driver at the time of this writing:
+
+	1. Up to 16 bidirectional endpoints (including the control
+	   pipe - ep0)
+	2. Flexible endpoint configuration
+	3. Simultaneous IN and OUT transfer support
+	4. Scatter-list support
+	5. Up to 256 TRBs [#trb]_ per endpoint
+	6. Support for all transfer types (*Control*, *Bulk*,
+	   *Interrupt*, and *Isochronous*)
+	7. SuperSpeed Bulk Streams
+	8. Link Power Management
+	9. Trace Events for debugging
+	10. DebugFS [#debugfs]_ interface
+
+These features have all been exercised with many of the **in-tree**
+gadget drivers. We have verified both *ConfigFS* [#configfs]_ and
+legacy gadget drivers.
+
+Driver Design
+==============
+
+The DWC3 driver sits on the *drivers/usb/dwc3/* directory. All files
+related to this driver are in this one directory. This makes it easy
+for new-comers to read the code and understand how it behaves.
+
+Because of DWC3's configuration flexibility, the driver is a little
+complex in some places but it should be rather straightforward to
+understand.
+
+The biggest part of the driver refers to the Gadget API.
+
+Known Limitations
+===================
+
+Like any other HW, DWC3 has its own set of limitations. To avoid
+constant questions about such problems, we decided to document them
+here and have a single location to where we could point users.
+
+OUT Transfer Size Requirements
+---------------------------------
+
+According to Synopsys Databook, all OUT transfer TRBs [#trb]_ must
+have their *size* field set to a value which is integer divisible by
+the endpoint's *wMaxPacketSize*. This means that *e.g.* in order to
+receive a Mass Storage *CBW* [#cbw]_, req->length must either be set
+to a value that's divisible by *wMaxPacketSize* (1024 on SuperSpeed,
+512 on HighSpeed, etc), or DWC3 driver must add a Chained TRB pointing
+to a throw-away buffer for the remaining length. Without this, OUT
+transfers will **NOT** start.
+
+Note that as of this writing, this won't be a problem because DWC3 is
+fully capable of appending a chained TRB for the remaining length and
+completely hide this detail from the gadget driver. It's still worth
+mentioning because this seems to be the largest source of queries
+about DWC3 and *non-working transfers*.
+
+TRB Ring Size Limitation
+-------------------------
+
+We, currently, have a hard limit of 256 TRBs [#trb]_ per endpoint,
+with the last TRB being a Link TRB [#link_trb]_ pointing back to the
+first. This limit is arbitrary but it has the benefit of adding up to
+exactly 4096 bytes, or 1 Page.
+
+DWC3 driver will try its best to cope with more than 255 requests and,
+for the most part, it should work normally. However this is not
+something that has been exercised very frequently. If you experience
+any problems, see section **Reporting Bugs** below.
+
+Reporting Bugs
+================
+
+Whenever you encounter a problem with DWC3, first and foremost you
+should make sure that:
+
+	1. You're running latest tag from `Linus' tree`_
+	2. You can reproduce the error without any out-of-tree changes
+	   to DWC3
+	3. You have checked that it's not a fault on the host machine
+
+After all these are verified, then here's how to capture enough
+information so we can be of any help to you.
+
+Required Information
+---------------------
+
+DWC3 relies exclusively on Trace Events for debugging. Everything is
+exposed there, with some extra bits being exposed to DebugFS
+[#debugfs]_.
+
+In order to capture DWC3's Trace Events you should run the following
+commands **before** plugging the USB cable to a host machine:
+
+.. code-block:: sh
+
+		 # mkdir -p /d
+		 # mkdir -p /t
+		 # mount -t debugfs none /d
+		 # mount -t tracefs none /t
+		 # echo 81920 > /t/buffer_size_kb
+		 # echo 1 > /t/events/dwc3/enable
+
+After this is done, you can connect your USB cable and reproduce the
+problem. As soon as the fault is reproduced, make a copy of files
+``trace`` and ``regdump``, like so:
+
+.. code-block:: sh
+
+		# cp /t/trace /root/trace.txt
+		# cat /d/*dwc3*/regdump > /root/regdump.txt
+
+Make sure to compress ``trace.txt`` and ``regdump.txt`` in a tarball
+and email it to `me`_ with `linux-usb`_ in Cc. If you want to be extra
+sure that I'll help you, write your subject line in the following
+format:
+
+	**[BUG REPORT] usb: dwc3: Bug while doing XYZ**
+
+On the email body, make sure to detail what you doing, which gadget
+driver you were using, how to reproduce the problem, what SoC you're
+using, which OS (and its version) was running on the Host machine.
+
+With all this information, we should be able to understand what's
+going on and be helpful to you.
+
+Debugging
+===========
+
+First and foremost a disclaimer::
+
+  DISCLAIMER: The information available on DebugFS and/or TraceFS can
+  change at any time at any Major Linux Kernel Release. If writing
+  scripts, do **NOT** assume information to be available in the
+  current format.
+
+With that out of the way, let's carry on.
+
+If you're willing to debug your own problem, you deserve a round of
+applause :-)
+
+Anyway, there isn't much to say here other than Trace Events will be
+really helpful in figuring out issues with DWC3. Also, access to
+Synopsys Databook will be **really** valuable in this case.
+
+A USB Sniffer can be helpful at times but it's not entirely required,
+there's a lot that can be understood without looking at the wire.
+
+Feel free to email `me`_ and Cc `linux-usb`_ if you need any help.
+
+``DebugFS``
+-------------
+
+``DebugFS`` is very good for gathering snapshots of what's going on
+with DWC3 and/or any endpoint.
+
+On DWC3's ``DebugFS`` directory, you will find the following files and
+directories:
+
+``ep[0..15]{in,out}/``
+``link_state``
+``regdump``
+``testmode``
+
+``link_state``
+``````````````
+
+When read, ``link_state`` will print out one of ``U0``, ``U1``,
+``U2``, ``U3``, ``SS.Disabled``, ``RX.Detect``, ``SS.Inactive``,
+``Polling``, ``Recovery``, ``Hot Reset``, ``Compliance``,
+``Loopback``, ``Reset``, ``Resume`` or ``UNKNOWN link state``.
+
+This file can also be written to in order to force link to one of the
+states above.
+
+``regdump``
+`````````````
+
+File name is self-explanatory. When read, ``regdump`` will print out a
+register dump of DWC3. Note that this file can be grepped to find the
+information you want.
+
+``testmode``
+``````````````
+
+When read, ``testmode`` will print out a name of one of the specified
+USB 2.0 Testmodes (``test_j``, ``test_k``, ``test_se0_nak``,
+``test_packet``, ``test_force_enable``) or the string ``no test`` in
+case no tests are currently being executed.
+
+In order to start any of these test modes, the same strings can be
+written to the file and DWC3 will enter the requested test mode.
+
+
+``ep[0..15]{in,out}``
+``````````````````````
+
+For each endpoint we expose one directory following the naming
+convention ``ep$num$dir`` *(ep0in, ep0out, ep1in, ...)*. Inside each
+of these directories you will find the following files:
+
+``descriptor_fetch_queue``
+``event_queue``
+``rx_fifo_queue``
+``rx_info_queue``
+``rx_request_queue``
+``transfer_type``
+``trb_ring``
+``tx_fifo_queue``
+``tx_request_queue``
+
+With access to Synopsys Databook, you can decode the information on
+them.
+
+``transfer_type``
+~~~~~~~~~~~~~~~~~~
+
+When read, ``transfer_type`` will print out one of ``control``,
+``bulk``, ``interrupt`` or ``isochronous`` depending on what the
+endpoint descriptor says. If the endpoint hasn't been enabled yet, it
+will print ``--``.
+
+``trb_ring``
+~~~~~~~~~~~~~
+
+When read, ``trb_ring`` will print out details about all TRBs on the
+ring. It will also tell you where our enqueue and dequeue pointers are
+located in the ring:
+
+.. code-block:: sh
+   
+		buffer_addr,size,type,ioc,isp_imi,csp,chn,lst,hwo
+		000000002c754000,481,normal,1,0,1,0,0,0         
+		000000002c75c000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c754000,481,normal,1,0,1,0,0,0         
+		000000002c75c000,481,normal,1,0,1,0,0,0         
+		000000002c784000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c784000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c754000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c784000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c784000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c754000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c75c000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c754000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c754000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c754000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c75c000,481,normal,1,0,1,0,0,0         
+		000000002c780000,481,normal,1,0,1,0,0,0         
+		000000002c784000,481,normal,1,0,1,0,0,0         
+		000000002c788000,481,normal,1,0,1,0,0,0         
+		000000002c78c000,481,normal,1,0,1,0,0,0         
+		000000002c790000,481,normal,1,0,1,0,0,0         
+		000000002c754000,481,normal,1,0,1,0,0,0         
+		000000002c758000,481,normal,1,0,1,0,0,0         
+		000000002c75c000,512,normal,1,0,1,0,0,1        D
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0       E 
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		0000000000000000,0,UNKNOWN,0,0,0,0,0,0         
+		00000000381ab000,0,link,0,0,0,0,0,1
+
+
+Trace Events
+-------------
+
+DWC3 also provides several trace events which help us gathering
+information about the behavior of the driver during runtime.
+
+In order to use these events, you must enable ``CONFIG_FTRACE`` in
+your kernel config.
+
+For details about how enable DWC3 events, see section **Reporting
+Bugs**.
+
+The following subsections will give details about each Event Class and
+each Event defined by DWC3.
+
+MMIO
+```````
+
+It is sometimes useful to look at every MMIO access when looking for
+bugs. Because of that, DWC3 offers two Trace Events (one for
+dwc3_readl() and one for dwc3_writel()). ``TP_printk`` follows::
+
+  TP_printk("addr %p value %08x", __entry->base + __entry->offset,
+  		__entry->value)
+
+Interrupt Events
+````````````````
+
+Every IRQ event can be logged and decoded into a human readable
+string. Because every event will be different, we don't give an
+example other than the ``TP_printk`` format used::
+
+  TP_printk("event (%08x): %s", __entry->event,
+  		dwc3_decode_event(__entry->event, __entry->ep0state))
+
+Control Request
+`````````````````
+
+Every USB Control Request can be logged to the trace buffer. The
+output format is::
+
+  TP_printk("%s", dwc3_decode_ctrl(__entry->bRequestType,
+  				__entry->bRequest, __entry->wValue,
+  				__entry->wIndex, __entry->wLength)
+  )
+
+Note that Standard Control Requests will be decoded into
+human-readable strings with their respective arguments. Class and
+Vendor requests will be printed out a sequence of 8 bytes in hex
+format.
+
+Lifetime of a ``struct usb_request``
+```````````````````````````````````````
+
+The entire lifetime of a ``struct usb_request`` can be tracked on the
+trace buffer. We have one event for each of allocation, free,
+queueing, dequeueing, and giveback. Output format is::
+
+  TP_printk("%s: req %p length %u/%u %s%s%s ==> %d",
+  	__get_str(name), __entry->req, __entry->actual, __entry->length,
+  	__entry->zero ? "Z" : "z",
+  	__entry->short_not_ok ? "S" : "s",
+  	__entry->no_interrupt ? "i" : "I",
+  	__entry->status
+  )
+
+Generic Commands
+````````````````````
+
+We can log and decode every Generic Command with its completion
+code. Format is::
+
+  TP_printk("cmd '%s' [%x] param %08x --> status: %s",
+  	dwc3_gadget_generic_cmd_string(__entry->cmd),
+  	__entry->cmd, __entry->param,
+  	dwc3_gadget_generic_cmd_status_string(__entry->status)
+  )
+
+Endpoint Commands
+````````````````````
+
+Endpoints commands can also be logged together with completion
+code. Format is::
+
+  TP_printk("%s: cmd '%s' [%d] params %08x %08x %08x --> status: %s",
+  	__get_str(name), dwc3_gadget_ep_cmd_string(__entry->cmd),
+  	__entry->cmd, __entry->param0,
+  	__entry->param1, __entry->param2,
+  	dwc3_ep_cmd_status_string(__entry->cmd_status)
+  )
+
+Lifetime of a ``TRB``
+``````````````````````
+
+A ``TRB`` Lifetime is simple. We are either preparing a ``TRB`` or
+completing it. With these two events, we can see how a ``TRB`` changes
+over time. Format is::
+
+  TP_printk("%s: %d/%d trb %p buf %08x%08x size %s%d ctrl %08x (%c%c%c%c:%c%c:%s)",
+  	__get_str(name), __entry->queued, __entry->allocated,
+  	__entry->trb, __entry->bph, __entry->bpl,
+  	({char *s;
+  	int pcm = ((__entry->size >> 24) & 3) + 1;
+  	switch (__entry->type) {
+  	case USB_ENDPOINT_XFER_INT:
+  	case USB_ENDPOINT_XFER_ISOC:
+  		switch (pcm) {
+  		case 1:
+  			s = "1x ";
+  			break;
+  		case 2:
+  			s = "2x ";
+  			break;
+  		case 3:
+  			s = "3x ";
+  			break;
+  		}
+  	default:
+  		s = "";
+  	} s; }),
+  	DWC3_TRB_SIZE_LENGTH(__entry->size), __entry->ctrl,
+  	__entry->ctrl & DWC3_TRB_CTRL_HWO ? 'H' : 'h',
+  	__entry->ctrl & DWC3_TRB_CTRL_LST ? 'L' : 'l',
+  	__entry->ctrl & DWC3_TRB_CTRL_CHN ? 'C' : 'c',
+  	__entry->ctrl & DWC3_TRB_CTRL_CSP ? 'S' : 's',
+  	__entry->ctrl & DWC3_TRB_CTRL_ISP_IMI ? 'S' : 's',
+  	__entry->ctrl & DWC3_TRB_CTRL_IOC ? 'C' : 'c',
+      dwc3_trb_type_string(DWC3_TRBCTL_TYPE(__entry->ctrl))
+  )  
+
+Lifetime of an Endpoint
+```````````````````````
+
+And endpoint's lifetime is summarized with enable and disable
+operations, both of which can be traced. Format is::
+
+  TP_printk("%s: mps %d/%d streams %d burst %d ring %d/%d flags %c:%c%c%c%c%c:%c:%c",
+  	__get_str(name), __entry->maxpacket,
+  	__entry->maxpacket_limit, __entry->max_streams,
+  	__entry->maxburst, __entry->trb_enqueue,
+  	__entry->trb_dequeue,
+  	__entry->flags & DWC3_EP_ENABLED ? 'E' : 'e',
+  	__entry->flags & DWC3_EP_STALL ? 'S' : 's',
+  	__entry->flags & DWC3_EP_WEDGE ? 'W' : 'w',
+  	__entry->flags & DWC3_EP_TRANSFER_STARTED ? 'B' : 'b',
+  	__entry->flags & DWC3_EP_PENDING_REQUEST ? 'P' : 'p',
+  	__entry->flags & DWC3_EP_END_TRANSFER_PENDING ? 'E' : 'e',
+  	__entry->direction ? '<' : '>'
+  )
+
+
+Structures, Methods and Definitions
+====================================
+
+.. kernel-doc:: drivers/usb/dwc3/core.h
+   :doc: main data structures
+   :internal:
+
+.. kernel-doc:: drivers/usb/dwc3/gadget.h
+   :doc: gadget-only helpers
+   :internal:
+
+.. kernel-doc:: drivers/usb/dwc3/gadget.c
+   :doc: gadget-side implementation
+   :internal:
+
+.. kernel-doc:: drivers/usb/dwc3/core.c
+   :doc: core driver (probe, PM, etc)
+   :internal:
+   
+.. [#trb] Transfer Request Block
+.. [#link_trb] Transfer Request Block pointing to another Transfer
+	       Request Block.
+.. [#debugfs] The Debug File System
+.. [#configfs] The Config File System
+.. [#cbw] Command Block Wrapper
+.. _Linus' tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
+.. _me: felipe.balbi@linux.intel.com
+.. _linux-usb: linux-usb@vger.kernel.org