Merge tag 'usb-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB/Thunderbolt/PHY driver updates from Greg KH:
 "Here is the big USB and Thunderbolt and PHY driver updates for
  5.6-rc1.

  With the advent of USB4, "Thunderbolt" has really become USB4, so the
  renaming of the Kconfig option and starting to share subsystem code
  has begun, hence both subsystems coming in through the same tree here.

  PHY driver updates also touched USB drivers, so that is coming in
  through here as well.

  Major stuff included in here are:
   - USB 4 initial support added (i.e. Thunderbolt)
   - musb driver updates
   - USB gadget driver updates
   - PHY driver updates
   - USB PHY driver updates
   - lots of USB serial stuff fixed up
   - USB typec updates
   - USB-IP fixes
   - lots of other smaller USB driver updates

  All of these have been in linux-next for a while now (the usb-serial
  tree is already tested in linux-next on its own before merged into
  here), with no reported issues"

[ Removed an incorrect compile test enablement for PHY_EXYNOS5250_SATA
  that causes configuration warnings    - Linus ]

* tag 'usb-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (207 commits)
  Doc: ABI: add usb charger uevent
  usb: phy: show USB charger type for user
  usb: cdns3: fix spelling mistake and rework grammar in text
  usb: phy: phy-gpio-vbus-usb: Convert to GPIO descriptors
  USB: serial: cyberjack: fix spelling mistake "To" -> "Too"
  USB: serial: ir-usb: simplify endpoint check
  USB: serial: ir-usb: make set_termios synchronous
  USB: serial: ir-usb: fix IrLAP framing
  USB: serial: ir-usb: fix link-speed handling
  USB: serial: ir-usb: add missing endpoint sanity check
  usb: typec: fusb302: fix "op-sink-microwatt" default that was in mW
  usb: typec: wcove: fix "op-sink-microwatt" default that was in mW
  usb: dwc3: pci: add ID for the Intel Comet Lake -V variant
  usb: typec: tcpci: mask event interrupts when remove driver
  usb: host: xhci-tegra: set MODULE_FIRMWARE for tegra186
  usb: chipidea: add inline for ci_hdrc_host_driver_init if host is not defined
  usb: chipidea: handle single role for usb role class
  usb: musb: fix spelling mistake: "periperal" -> "peripheral"
  phy: ti: j721e-wiz: Fix build error without CONFIG_OF_ADDRESS
  USB: usbfs: Always unlink URBs in reverse order
  ...

1 files changed, 25 insertions, 5 deletions

diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst
index 898ad78f3cc7..10c4f0ce2ad0 100644
--- a/Documentation/admin-guide/thunderbolt.rst
+++ b/Documentation/admin-guide/thunderbolt.rst
@@ -1,6 +1,28 @@
-=============
- Thunderbolt
-=============
+.. SPDX-License-Identifier: GPL-2.0
+
+======================
+ USB4 and Thunderbolt
+======================
+USB4 is the public specification based on Thunderbolt 3 protocol with
+some differences at the register level among other things. Connection
+manager is an entity running on the host router (host controller)
+responsible for enumerating routers and establishing tunnels. A
+connection manager can be implemented either in firmware or software.
+Typically PCs come with a firmware connection manager for Thunderbolt 3
+and early USB4 capable systems. Apple systems on the other hand use
+software connection manager and the later USB4 compliant devices follow
+the suit.
+
+The Linux Thunderbolt driver supports both and can detect at runtime which
+connection manager implementation is to be used. To be on the safe side the
+software connection manager in Linux also advertises security level
+``user`` which means PCIe tunneling is disabled by default. The
+documentation below applies to both implementations with the exception that
+the software connection manager only supports ``user`` security level and
+is expected to be accompanied with an IOMMU based DMA protection.
+
+Security levels and how to use them
+-----------------------------------
 The interface presented here is not meant for end users. Instead there
 should be a userspace tool that handles all the low-level details, keeps
 a database of the authorized devices and prompts users for new connections.
@@ -18,8 +40,6 @@ This will authorize all devices automatically when they appear. However,
 keep in mind that this bypasses the security levels and makes the system
 vulnerable to DMA attacks.
 
-Security levels and how to use them
------------------------------------
 Starting with Intel Falcon Ridge Thunderbolt controller there are 4
 security levels available. Intel Titan Ridge added one more security level
 (usbonly). The reason for these is the fact that the connected devices can