Merge tag 'thunderbolt-for-v6.11-rc1' of ssh://gitolite.kernel.org/pu…

…b/scm/linux/kernel/git/westeri/thunderbolt into usb-next

Mika writes:

thunderbolt: Changes for v6.11 merge window

This includes following USB4/Thunderbolt changes for the v6.11 merge
window:

  - Add receiver lane margining support for retimers
  - Add sideband register access to debugfs
  - Minor cleanups.

All these have been in linux-next with no reported issues.

* tag 'thunderbolt-for-v6.11-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt:
  thunderbolt: debugfs: Use FIELD_GET()
  thunderbolt: Add receiver lane margining support for retimers
  thunderbolt: Make margining functions accept target and retimer index
  thunderbolt: Split out margining from USB4 port
  thunderbolt: Add sideband register access to debugfs
  thunderbolt: Make usb4_port_sb_read/write() available outside of usb4.c
  thunderbolt: Move usb4_port_margining_caps() declaration into correct place
  thunderbolt: Mention Thunderbolt/USB4 debugging tools in Kconfig

drivers/thunderbolt/Kconfig

@@ -22,20 +22,25 @@ config USB4_DEBUGFS_WRITE
 	bool "Enable write by debugfs to configuration spaces (DANGEROUS)"
 	help
 	  Enables writing to device configuration registers through
-	  debugfs interface.
+	  debugfs interface. You can use tools such as Thunderbolt/USB4
+	  debugging tools to access these registers. For more
+	  information see:
+
+	    https://github.com/intel/tbtools
 
 	  Only enable this if you know what you are doing! Never enable
 	  this for production systems or distro kernels.
 
 config USB4_DEBUGFS_MARGINING
-	bool "Expose receiver lane margining operations under USB4 ports (DANGEROUS)"
+	bool "Expose receiver lane margining operations under USB4 ports and retimers (DANGEROUS)"
 	depends on DEBUG_FS
 	depends on USB4_DEBUGFS_WRITE
 	help
-	  Enables hardware and software based receiver lane margining support
-	  under each USB4 port. Used for electrical quality and robustness
-	  validation during manufacturing. Should not be enabled by distro
-	  kernels.
+	  Enables hardware and software based receiver lane margining
+	  support under each USB4 port and retimer, including retimers
+	  on the other side of the cable. Used for electrical quality
+	  and robustness validation during manufacturing. Should not be
+	  enabled by distro kernels.
 
 config USB4_KUNIT_TEST
 	bool "KUnit tests" if !KUNIT_ALL_TESTS