linux.git/drivers/thunderbolt, branch master

Merge tag 'thunderbolt-for-v6.12-rc7' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-linus

2024-11-07T15:11:57+00:00

thunderbolt: Fixes for v6.12-rc7

This includes following USB4/Thunderbolt fixes for v6.12-rc7:

  - Fix for retimer enumeration.
  - Fix connection issue with Pluggable UD-4VPD USB4 dock.

Both have been in linux-next with no reported issues.

* tag 'thunderbolt-for-v6.12-rc7' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt:
  thunderbolt: Fix connection issue with Pluggable UD-4VPD dock
  thunderbolt: Add only on-board retimers when !CONFIG_USB4_DEBUGFS_MARGINING

thunderbolt: Fix connection issue with Pluggable UD-4VPD dock

2024-11-05T14:29:47+00:00

Rick reported that his Pluggable USB4 dock does not work anymore after
upgrading to v6.10 kernel.

It looks like commit c6ca1ac9f472 ("thunderbolt: Increase sideband
access polling delay") makes the device router enumeration happen later
than what might be expected by the dock (although there is no such limit
in the USB4 spec) which probably makes it assume there is something
wrong with the high-speed link and reset it. After the link is reset the
same issue happens again and again.

For this reason lower the sideband access delay from 5ms to 1ms. This
seems to work fine according to Rick's testing.

Reported-by: Rick Lahaye 
Closes: https://lore.kernel.org/linux-usb/000f01db247b$d10e1520$732a3f60$@581238.xyz/
Tested-by: Rick Lahaye 
Fixes: c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")
Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman 
Reviewed-by: Mario Limonciello 
Signed-off-by: Mika Westerberg

thunderbolt: Add only on-board retimers when !CONFIG_USB4_DEBUGFS_MARGINING

2024-10-29T05:48:42+00:00

Normally there is no need to enumerate retimers on the other side of the
cable. This is only needed in special cases where user wants to run
receiver lane margining against the downstream facing port of a retimer.
Furthermore this might confuse the userspace tools such as fwupd because
it cannot read the information it expects from these retimers.

Fix this by changing the retimer enumeration code to add only on-board
retimers when CONFIG_USB4_DEBUGFS_MARGINING is not enabled.

Reported-by: AceLan Kao 
Tested-by: AceLan Kao 
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219420
Cc: stable@vger.kernel.org
Fixes: ff6ab055e070 ("thunderbolt: Add receiver lane margining support for retimers")
Signed-off-by: Mika Westerberg

thunderbolt: Honor TMU requirements in the domain when setting TMU mode

2024-10-21T06:42:42+00:00

Currently, when configuring TMU (Time Management Unit) mode of a given
router, we take into account only its own TMU requirements ignoring
other routers in the domain. This is problematic if the router we are
configuring has lower TMU requirements than what is already configured
in the domain.

In the scenario below, we have a host router with two USB4 ports: A and
B. Port A connected to device router #1 (which supports CL states) and
existing DisplayPort tunnel, thus, the TMU mode is HiFi uni-directional.

1. Initial topology

          [Host]
         A/
         /
 [Device #1]
   /
Monitor

2. Plug in device #2 (that supports CL states) to downstream port B of
   the host router

         [Host]
        A/    B\
        /       \
 [Device #1]    [Device #2]
   /
Monitor

The TMU mode on port B and port A will be configured to LowRes which is
not what we want and will cause monitor to start flickering.

To address this we first scan the domain and search for any router
configured to HiFi uni-directional mode, and if found, configure TMU
mode of the given router to HiFi uni-directional as well.

Cc: stable@vger.kernel.org
Signed-off-by: Gil Fine 
Signed-off-by: Mika Westerberg

thunderbolt: Fix KASAN reported stack out-of-bounds read in tb_retimer_scan()

2024-10-11T11:23:15+00:00

KASAN reported following issue:

 BUG: KASAN: stack-out-of-bounds in tb_retimer_scan+0xffe/0x1550 [thunderbolt]
 Read of size 4 at addr ffff88810111fc1c by task kworker/u56:0/11
 CPU: 0 UID: 0 PID: 11 Comm: kworker/u56:0 Tainted: G     U             6.11.0+ #1387
 Tainted: [U]=USER
 Workqueue: thunderbolt0 tb_handle_hotplug [thunderbolt]
 Call Trace:
  
  dump_stack_lvl+0x6c/0x90
  print_report+0xd1/0x630
  kasan_report+0xdb/0x110
  __asan_report_load4_noabort+0x14/0x20
  tb_retimer_scan+0xffe/0x1550 [thunderbolt]
  tb_scan_port+0xa6f/0x2060 [thunderbolt]
  tb_handle_hotplug+0x17b1/0x3080 [thunderbolt]
  process_one_work+0x626/0x1100
  worker_thread+0x6c8/0xfa0
  kthread+0x2c8/0x3a0
  ret_from_fork+0x3a/0x80
  ret_from_fork_asm+0x1a/0x30

This happens because the loop variable still gets incremented by one so
max becomes 3 instead of 2, and this makes the second loop read past the
the array declared on the stack.

Fix this by assigning to max directly in the loop body.

Fixes: ff6ab055e070 ("thunderbolt: Add receiver lane margining support for retimers")
CC: stable@vger.kernel.org
Signed-off-by: Mika Westerberg

Merge tag 'thunderbolt-for-v6.12-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-next

2024-09-11T13:17:43+00:00

Mika writes:

thunderbolt: Changes for v6.12 merge window

This includes following USB4/Thunderbolt changes for the v6.12 merge
window:

  - Improvements for software receiver lane margining
  - Enable support for optional voltage offset range for receiver lane
    margining.

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

* tag 'thunderbolt-for-v6.12-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt:
  thunderbolt: Improve software receiver lane margining
  thunderbolt: Add optional voltage offset range for receiver lane margining
  thunderbolt: Consolidate margining parameters into a structure
  thunderbolt: Add missing usb4_port_sb_read() to usb4_port_sw_margin()

thunderbolt: Don't create device link from USB4 Host Interface to USB3 xHC host

2024-09-03T07:54:39+00:00

USB core will create device links between tunneled USB3 devices and
USB4 Host Interface during USB device creation.

Those device links are removed with the tunneled USB3 devices, allowing
USB4 Host Interface to runtime suspend if USB3 tunnels are not used.

So remove device link creation between USB4 Host Interface and USB3 xHC
during NHI probe

Reported-by: Rajaram Regupathy 
Reported-by: Saranya Gopal 
Tested-by: Saranya Gopal 
Acked-by: Mika Westerberg 
Signed-off-by: Mathias Nyman 
Link: https://lore.kernel.org/r/20240830152630.3943215-5-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

thunderbolt: Improve software receiver lane margining

2024-08-22T04:32:06+00:00

USB4 specification defines the metadata needed to perform software
margining, as well as the necessary steps which include waiting for
dwell time.

- Add dwell_time attribute to set the wait time while performing
  margining and checking for link errors.
- Add error_counter attribute to configure error counter prior to
  margining test.
- Add voltage_time_offset attribute to set the voltage or time offset
  steps before performing the software margining test.
- Perform software margining test for dwell duration, break if there are
  link errors, stop the clocks and provide results.

Below is a minimalistic example how this can be used. Note these values
are just examples. The exact values in practice depend on host specific
capabilities and the type of measurement to be performed.

  # cd /sys/kernel/debug/thunderbolt/ROUTER/portX/margining/
  # echo software > mode
  # echo 400 > dwell_time
  # echo 1 > run

As usual the results attribute contains the results of a succesfull run.

Signed-off-by: R Kannappan 
Co-developed-by: Rene Sapiens 
Signed-off-by: Rene Sapiens 
Co-developed-by: Aapo Vienamo 
Signed-off-by: Aapo Vienamo 
Signed-off-by: Mika Westerberg

thunderbolt: Add optional voltage offset range for receiver lane margining

2024-08-22T04:32:06+00:00

Add optional extended voltage offset range support for software and
hardware margining as defined by the USB4 specification.

If supported, it can be enabled like below:

 # cd /sys/kernel/debug/thunderbolt/ROUTER/portX/margining/
 # echo Y > optional_voltage_offset

Signed-off-by: Rene Sapiens 
Co-developed-by: R Kannappan 
Signed-off-by: R Kannappan 
Co-developed-by: Aapo Vienamo 
Signed-off-by: Aapo Vienamo 
Signed-off-by: Mika Westerberg

thunderbolt: Consolidate margining parameters into a structure

2024-08-22T04:32:06+00:00

Consolidate the hardware and software margining parameters into a single
structure to reduce the number of parameters passed to the margining
functions.

Signed-off-by: Rene Sapiens 
Co-developed-by: Aapo Vienamo 
Signed-off-by: Aapo Vienamo 
Signed-off-by: Mika Westerberg