linux-stable.git/drivers/thunderbolt/switch.c, branch v6.8

thunderbolt: Fix NULL pointer dereference in tb_port_update_credits()

2024-02-16T08:36:51+00:00

Olliver reported that his system crashes when plugging in Thunderbolt 1
device:

 BUG: kernel NULL pointer dereference, address: 0000000000000020
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP NOPTI
 RIP: 0010:tb_port_do_update_credits+0x1b/0x130 [thunderbolt]
 Call Trace:
  
  ? __die+0x23/0x70
  ? page_fault_oops+0x171/0x4e0
  ? exc_page_fault+0x7f/0x180
  ? asm_exc_page_fault+0x26/0x30
  ? tb_port_do_update_credits+0x1b/0x130
  ? tb_switch_update_link_attributes+0x83/0xd0
  tb_switch_add+0x7a2/0xfe0
  tb_scan_port+0x236/0x6f0
  tb_handle_hotplug+0x6db/0x900
  process_one_work+0x171/0x340
  worker_thread+0x27b/0x3a0
  ? __pfx_worker_thread+0x10/0x10
  kthread+0xe5/0x120
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x31/0x50
  ? __pfx_kthread+0x10/0x10
  ret_from_fork_asm+0x1b/0x30
  

This is due the fact that some Thunderbolt 1 devices only have one lane
adapter. Fix this by checking for the lane 1 before we read its credits.

Reported-by: Olliver Schinagl 
Closes: https://lore.kernel.org/linux-usb/c24c7882-6254-4e68-8f22-f3e8f65dc84f@schinagl.nl/
Fixes: 81af2952e606 ("thunderbolt: Add support for asymmetric link")
Cc: stable@vger.kernel.org
Cc: Gil Fine 
Signed-off-by: Mika Westerberg

Merge tag 'thunderbolt-for-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into char-misc-next

2024-01-02T13:25:05+00:00

Mika writes:

thunderbolt: Changes for v6.8 merge window

This includes following USB4/Thunderbolt changes for the v6.8 merge
window:

  - Intel Lunar Lake support
  - PCIe tunneling improvements
  - DisplayPort tunneling improvements
  - Asymmetric switching improvements
  - Couple of minor fixes and cleanups.

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

* tag 'thunderbolt-for-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt:
  thunderbolt: Reduce retry timeout to speed up boot for some devices
  thunderbolt: Keep link as asymmetric if preferred by hardware
  thunderbolt: Add support for Intel Lunar Lake
  thunderbolt: Disable PCIe extended encapsulation upon teardown properly
  thunderbolt: Make PCIe tunnel setup and teardown follow CM guide
  thunderbolt: Improve logging when DisplayPort resource is added due to hotplug
  thunderbolt: Use tb_dp_read_cap() to read DP_COMMON_CAP as well
  thunderbolt: Disable CL states only when actually needed
  thunderbolt: Transition link to asymmetric only when both sides support it
  thunderbolt: Log XDomain link speed and width
  thunderbolt: Move width_name() helper to tb.h
  thunderbolt: Handle lane bonding of Gen 4 XDomain links properly
  thunderbolt: Unwind TMU configuration if tb_switch_set_tmu_mode_params() fails
  thunderbolt: Remove duplicated re-assignment of pointer 'out'

thunderbolt: Keep link as asymmetric if preferred by hardware

2023-12-22T10:58:39+00:00

In case of the link is brought up as asymmetric (due to hardware preference), we
honor that and don't transition it to symmetric, unless a router with symmetric
link got plugged below, in the topology (and a bandwidth allows transition to
symmetric).

Signed-off-by: Gil Fine 
Signed-off-by: Mika Westerberg

thunderbolt: Move width_name() helper to tb.h

2023-12-14T06:07:44+00:00

We are going to use it in subsequent patches, so make it available outside of
switch.c. Also, change the name to tb_width_name() to follow the naming
conventions.

Signed-off-by: Gil Fine 
Signed-off-by: Mika Westerberg

thunderbolt: Send uevent after asymmetric/symmetric switch

2023-11-17T11:05:57+00:00

We should send uevent to userspace whenever the link speed or width
changes but tb_switch_asym_enable() and tb_switch_asym_disable() set the
sw->link_width already so tb_switch_update_link_attributes() never
noticed the change.

Fix this so that we let tb_switch_update_link_attributes() update the
fields accordingly.

Fixes: 81af2952e606 ("thunderbolt: Add support for asymmetric link")
Reported-by: Pengfei Xu 
Tested-by: Pengfei Xu 
Signed-off-by: Mika Westerberg

thunderbolt: Set lane bonding bit only for downstream port

2023-11-17T11:05:57+00:00

Fix the lane bonding procedure to follow the steps described in USB4
Connection Manager guide. Hence, set the lane bonding bit only for
downstream port. This is needed for certain ASMedia device, otherwise
lane bonding fails and the device disconnects.

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

Merge tag 'thunderbolt-for-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-next

2023-10-27T09:41:07+00:00

Mika writes:

thunderbolt: Changes for v6.7 merge window

This includes following USB4/Thunderbolt changes for the v6.7 merge
window:

  - Configure asymmetric link if the DisplayPort bandwidth requires so
  - Enable path power management packet support for USB4 v2 routers
  - Make the bandwidth reservations to follow the USB4 v2 connection
    manager guide suggestions
  - DisplayPort tunneling improvements
  - Small cleanups and improvements around the driver.

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

* tag 'thunderbolt-for-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt: (25 commits)
  thunderbolt: Fix one kernel-doc comment
  thunderbolt: Configure asymmetric link if needed and bandwidth allows
  thunderbolt: Add support for asymmetric link
  thunderbolt: Introduce tb_switch_depth()
  thunderbolt: Introduce tb_for_each_upstream_port_on_path()
  thunderbolt: Introduce tb_port_path_direction_downstream()
  thunderbolt: Set path power management packet support bit for USB4 v2 routers
  thunderbolt: Change bandwidth reservations to comply USB4 v2
  thunderbolt: Make is_gen4_link() available to the rest of the driver
  thunderbolt: Use weight constants in tb_usb3_consumed_bandwidth()
  thunderbolt: Use constants for path weight and priority
  thunderbolt: Add DP IN added last in the head of the list of DP resources
  thunderbolt: Create multiple DisplayPort tunnels if there are more DP IN/OUT pairs
  thunderbolt: Log NVM version of routers and retimers
  thunderbolt: Use tb_tunnel_xxx() log macros in tb.c
  thunderbolt: Expose tb_tunnel_xxx() log macros to the rest of the driver
  thunderbolt: Use tb_tunnel_dbg() where possible to make logging more consistent
  thunderbolt: Fix typo of HPD bit for Hot Plug Detect
  thunderbolt: Fix typo in enum tb_link_width kernel-doc
  thunderbolt: Fix debug log when DisplayPort adapter not available for pairing
  ...

thunderbolt: Add support for asymmetric link

2023-10-20T15:18:01+00:00

USB4 v2 spec defines a Gen 4 link that can operate as an aggregated
symmetric (80/80G) or asymmetric (120/40G). When the link is asymmetric,
the USB4 port on one side of the link operates with three TX lanes and
one RX lane, while the USB4 port on the opposite side of the link
operates with three RX lanes and one TX lane.

Add support for the asymmetric link and provide functions that can be
used to transition the link to asymmetric and back.

Signed-off-by: Gil Fine 
Co-developed-by: Mika Westerberg 
Signed-off-by: Mika Westerberg

thunderbolt: Make is_gen4_link() available to the rest of the driver

2023-10-20T15:18:01+00:00

Rework the function to return the link generation, update the name to
tb_port_get_link_generation(), and make available to the rest of the
driver. This is needed in the subsequent patches.

Signed-off-by: Gil Fine 
Signed-off-by: Mika Westerberg

thunderbolt: Log NVM version of routers and retimers

2023-10-13T05:49:13+00:00

This is useful when debugging possible issues.

Signed-off-by: Gil Fine 
Signed-off-by: Mika Westerberg