linux-stable.git/Documentation/driver-api, branch v6.12.97

PCI: Move Resizable BAR code to rebar.c

2026-07-24T14:11:49+00:00

[ Upstream commit 9f71938cd77f32a448f40a288e409eca60e55486 ]

For lack of a better place to put it, Resizable BAR code has been placed
inside pci.c and setup-res.c that do not use it for anything.  Upcoming
changes are going to add more Resizable BAR related functions, increasing
the code size.

As pci.c is huge as is, move the Resizable BAR related code and the BAR
resize code from setup-res.c to rebar.c.

Signed-off-by: Ilpo Järvinen 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Christian König 
Link: https://patch.msgid.link/20251113180053.27944-2-ilpo.jarvinen@linux.intel.com
Stable-dep-of: ee7471fe968d ("PCI: Skip Resizable BAR restore on read error")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

dpll: add reference-sync netlink attribute

2026-07-24T14:11:01+00:00

[ Upstream commit 7f15ee35972dd3dee37704bfd0f136290f6d63d9 ]

Add new netlink attribute to allow user space configuration of reference
sync pin pairs, where both pins are used to provide one clock signal
consisting of both: base frequency and sync signal.

Reviewed-by: Przemek Kitszel 
Reviewed-by: Milena Olech 
Reviewed-by: Jiri Pirko 
Signed-off-by: Arkadiusz Kubalewski 
Link: https://patch.msgid.link/20250626135219.1769350-2-arkadiusz.kubalewski@intel.com
Signed-off-by: Jakub Kicinski 
Stable-dep-of: 32239d600236 ("dpll: fix stale iteration in dpll_pin_on_pin_unregister()")
Signed-off-by: Sasha Levin

nvdimm/btt: Handle preemption in BTT lane acquisition

2026-07-24T14:10:53+00:00

[ Upstream commit 8d4b989d9c9afe5f185aa5853b666fc4617afe9e ]

BTT lanes serialize access to per-lane metadata and workspace state
during BTT I/O. The btt-check unit test reports data mismatches during
BTT writes due to a race in lane acquisition that can lead to silent
data corruption.

The existing lane model uses a spinlock together with a per-CPU
recursion count. That recursion model stopped being valid after BTT
lanes became preemptible: another task can run on the same CPU,
observe a non-zero recursion count, bypass locking, and use the same
lane concurrently.

BTT lanes are also held across arena_write_bytes() calls. That path
reaches nsio_rw_bytes(), which flushes writes with nvdimm_flush().
Some provider flush callbacks can sleep, making a spinlock the wrong
primitive for the lane lifetime.

Replace the spinlock-based recursion model with a dynamically
allocated per-lane mutex array and take the lane lock
unconditionally.

Add might_sleep() to catch any future atomic-context caller.

Found with the ndctl unit test btt-check.sh.

Fixes: 36c75ce3bd29 ("nd_btt: Make BTT lanes preemptible")
Assisted-by: Claude-Sonnet:4.5
Tested-by: Aboorva Devarajan 
Reviewed-by: Aboorva Devarajan 
Reviewed-by: Vishal Verma 
Reviewed-by: Dave Jiang 
Link: https://patch.msgid.link/20260528021625.618462-1-alison.schofield@intel.com
Signed-off-by: Alison Schofield 
Signed-off-by: Sasha Levin

gpiolib-acpi: Update file references in the Documentation and MAINTAINERS

2026-02-11T12:40:29+00:00

commit ec0c0aab15243bbc6140a7cedd01e2dd9ad19878 upstream.

The recent changes in the gpiolib-acpi.c need also updates in the Documentation
and MAINTAINERS. Do the necessary changes here.

Fixes: babb541af627 ("gpiolib: acpi: Move quirks to a separate file")
Reported-by: Stephen Rothwell 
Closes: https://lore.kernel.org/r/20250516193436.09bdf8cc@canb.auug.org.au
Reviewed-by: Randy Dunlap 
Tested-by: Randy Dunlap 
Acked-by: Ilpo Järvinen 
Signed-off-by: Andy Shevchenko 
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

soundwire: stream: extend sdw_alloc_stream() to take 'type' parameter

2026-01-08T09:15:04+00:00

[ Upstream commit dc90bbefa792031d89fe2af9ad4a6febd6be96a9 ]

In the existing definition of sdw_stream_runtime, the 'type' member is
never set and defaults to PCM. To prepare for the BPT/BRA support, we
need to special-case streams and make use of the 'type'.

No functional change for now, the implicit PCM type is now explicit.

Signed-off-by: Pierre-Louis Bossart 
Signed-off-by: Bard Liao 
Reviewed-by: Péter Ujfalusi 
Reviewed-by: Liam Girdwood 
Reviewed-by: Ranjani Sridharan 
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul 
Stable-dep-of: bcba17279327 ("ASoC: qcom: sdw: fix memory leak for sdw_stream_runtime")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

tty: fix tty_port_tty_*hangup() kernel-doc

2026-01-08T09:15:01+00:00

commit 6241b49540a65a6d5274fa938fd3eb4cbfe2e076 upstream.

The commit below added a new helper, but omitted to move (and add) the
corressponding kernel-doc. Do it now.

Signed-off-by: "Jiri Slaby (SUSE)" 
Fixes: 2b5eac0f8c6e ("tty: introduce and use tty_port_tty_vhangup() helper")
Link: https://lore.kernel.org/all/b23d566c-09dc-7374-cc87-0ad4660e8b2e@linux.intel.com/
Reported-by: Ilpo Järvinen 
Cc: Jonathan Corbet 
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/r/20250624080641.509959-6-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman

serial: mctrl_gpio: split disable_ms into sync and no_sync APIs

2025-05-29T09:02:45+00:00

[ Upstream commit 1bd2aad57da95f7f2d2bb52f7ad15c0f4993a685 ]

The following splat has been observed on a SAMA5D27 platform using
atmel_serial:

BUG: sleeping function called from invalid context at kernel/irq/manage.c:738
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 27, name: kworker/u5:0
preempt_count: 1, expected: 0
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last  enabled at (0): [<00000000>] 0x0
hardirqs last disabled at (0): [] copy_process+0x1c4c/0x7bec
softirqs last  enabled at (0): [] copy_process+0x1ca0/0x7bec
softirqs last disabled at (0): [<00000000>] 0x0
CPU: 0 UID: 0 PID: 27 Comm: kworker/u5:0 Not tainted 6.13.0-rc7+ #74
Hardware name: Atmel SAMA5
Workqueue: hci0 hci_power_on [bluetooth]
Call trace:
  unwind_backtrace from show_stack+0x18/0x1c
  show_stack from dump_stack_lvl+0x44/0x70
  dump_stack_lvl from __might_resched+0x38c/0x598
  __might_resched from disable_irq+0x1c/0x48
  disable_irq from mctrl_gpio_disable_ms+0x74/0xc0
  mctrl_gpio_disable_ms from atmel_disable_ms.part.0+0x80/0x1f4
  atmel_disable_ms.part.0 from atmel_set_termios+0x764/0x11e8
  atmel_set_termios from uart_change_line_settings+0x15c/0x994
  uart_change_line_settings from uart_set_termios+0x2b0/0x668
  uart_set_termios from tty_set_termios+0x600/0x8ec
  tty_set_termios from ttyport_set_flow_control+0x188/0x1e0
  ttyport_set_flow_control from wilc_setup+0xd0/0x524 [hci_wilc]
  wilc_setup [hci_wilc] from hci_dev_open_sync+0x330/0x203c [bluetooth]
  hci_dev_open_sync [bluetooth] from hci_dev_do_open+0x40/0xb0 [bluetooth]
  hci_dev_do_open [bluetooth] from hci_power_on+0x12c/0x664 [bluetooth]
  hci_power_on [bluetooth] from process_one_work+0x998/0x1a38
  process_one_work from worker_thread+0x6e0/0xfb4
  worker_thread from kthread+0x3d4/0x484
  kthread from ret_from_fork+0x14/0x28

This warning is emitted when trying to toggle, at the highest level,
some flow control (with serdev_device_set_flow_control) in a device
driver. At the lowest level, the atmel_serial driver is using
serial_mctrl_gpio lib to enable/disable the corresponding IRQs
accordingly.  The warning emitted by CONFIG_DEBUG_ATOMIC_SLEEP is due to
disable_irq (called in mctrl_gpio_disable_ms) being possibly called in
some atomic context (some tty drivers perform modem lines configuration
in regions protected by port lock).

Split mctrl_gpio_disable_ms into two differents APIs, a non-blocking one
and a blocking one. Replace mctrl_gpio_disable_ms calls with the
relevant version depending on whether the call is protected by some port
lock.

Suggested-by: Jiri Slaby 
Signed-off-by: Alexis Lothoré 
Acked-by: Richard Genoud 
Link: https://lore.kernel.org/r/20250217-atomic_sleep_mctrl_serial_gpio-v3-1-59324b313eef@bootlin.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

crypto: iaa - Fix IAA disabling that occurs when sync_mode is set to 'async'

2025-02-08T08:57:30+00:00

[ Upstream commit 4ebd9a5ca478673cfbb38795cc5b3adb4f35fe04 ]

With the latest mm-unstable, setting the iaa_crypto sync_mode to 'async'
causes crypto testmgr.c test_acomp() failure and dmesg call traces, and
zswap being unable to use 'deflate-iaa' as a compressor:

echo async > /sys/bus/dsa/drivers/crypto/sync_mode

[  255.271030] zswap: compressor deflate-iaa not available
[  369.960673] INFO: task cryptomgr_test:4889 blocked for more than 122 seconds.
[  369.970127]       Not tainted 6.13.0-rc1-mm-unstable-12-16-2024+ #324
[  369.977411] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  369.986246] task:cryptomgr_test  state:D stack:0     pid:4889  tgid:4889  ppid:2      flags:0x00004000
[  369.986253] Call Trace:
[  369.986256]  
[  369.986260]  __schedule+0x45c/0xfa0
[  369.986273]  schedule+0x2e/0xb0
[  369.986277]  schedule_timeout+0xe7/0x100
[  369.986284]  ? __prepare_to_swait+0x4e/0x70
[  369.986290]  wait_for_completion+0x8d/0x120
[  369.986293]  test_acomp+0x284/0x670
[  369.986305]  ? __pfx_cryptomgr_test+0x10/0x10
[  369.986312]  alg_test_comp+0x263/0x440
[  369.986315]  ? sched_balance_newidle+0x259/0x430
[  369.986320]  ? __pfx_cryptomgr_test+0x10/0x10
[  369.986323]  alg_test.part.27+0x103/0x410
[  369.986326]  ? __schedule+0x464/0xfa0
[  369.986330]  ? __pfx_cryptomgr_test+0x10/0x10
[  369.986333]  cryptomgr_test+0x20/0x40
[  369.986336]  kthread+0xda/0x110
[  369.986344]  ? __pfx_kthread+0x10/0x10
[  369.986346]  ret_from_fork+0x2d/0x40
[  369.986355]  ? __pfx_kthread+0x10/0x10
[  369.986358]  ret_from_fork_asm+0x1a/0x30
[  369.986365]  

This happens because the only async polling without interrupts that
iaa_crypto currently implements is with the 'sync' mode. With 'async',
iaa_crypto calls to compress/decompress submit the descriptor and return
-EINPROGRESS, without any mechanism in the driver to poll for
completions. Hence callers such as test_acomp() in crypto/testmgr.c or
zswap, that wrap the calls to crypto_acomp_compress() and
crypto_acomp_decompress() in synchronous wrappers, will block
indefinitely. Even before zswap can notice this problem, the crypto
testmgr.c's test_acomp() will fail and prevent registration of
"deflate-iaa" as a valid crypto acomp algorithm, thereby disallowing the
use of "deflate-iaa" as a zswap compress (zswap will fall-back to the
default compressor in this case).

To fix this issue, this patch modifies the iaa_crypto sync_mode set
function to treat 'async' equivalent to 'sync', so that the correct and
only supported driver async polling without interrupts implementation is
enabled, and zswap can use 'deflate-iaa' as the compressor.

Hence, with this patch, this is what will happen:

echo async > /sys/bus/dsa/drivers/crypto/sync_mode
cat /sys/bus/dsa/drivers/crypto/sync_mode
sync

There are no crypto/testmgr.c test_acomp() errors, no call traces and zswap
can use 'deflate-iaa' without any errors. The iaa_crypto documentation has
also been updated to mention this caveat with 'async' and what to expect
with this fix.

True iaa_crypto async polling without interrupts is enabled in patch
"crypto: iaa - Implement batch_compress(), batch_decompress() API in
iaa_crypto." [1] which is under review as part of the "zswap IAA compress
batching" patch-series [2]. Until this is merged, we would appreciate it if
this current patch can be considered for a hotfix.

[1]: https://patchwork.kernel.org/project/linux-mm/patch/20241221063119.29140-5-kanchana.p.sridhar@intel.com/
[2]: https://patchwork.kernel.org/project/linux-mm/list/?series=920084

Fixes: 09646c98d ("crypto: iaa - Add irq support for the crypto async interface")
Signed-off-by: Kanchana P Sridhar 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

platform/x86: wmi: Update WMI driver API documentation

2024-10-06T10:48:52+00:00

The WMI driver core now passes the WMI event data to legacy notify
handlers, so WMI devices sharing notification IDs are now being
handled properly.

Fixes: e04e2b760ddb ("platform/x86: wmi: Pass event data directly to legacy notify handlers")
Signed-off-by: Armin Wolf 
Link: https://lore.kernel.org/r/20241005213825.701887-1-W_Armin@gmx.de
Signed-off-by: Hans de Goede

Merge tag 'cxl-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

2024-09-27T18:42:03+00:00

Pull compute express link (cxl) updates from Dave Jiang:
 "Major changes address HDM decoder initialization from DVSEC ranges,
  refactoring the code related to cxl mailboxes to be independent of the
  memory devices, and adding support for shared upstream link
  access_coordinate calculation, as well as a change to remove locking
  from memory notifier callback.

  In addition, a number of misc cleanups and refactoring of the code are
  also included.

  Address HDM decoder initialization from DVSEC ranges:
   - Only register non-zero DVSEC ranges
   - Remove duplicate implementation of waiting for memory_info_valid
   - Simplify the checking of mem_enabled in  cxl_hdm_decode_init()

  Refactor the code related to cxl mailboxes to be independent of the memory devices:
   - Move cxl headers in include/linux/ to include/cxl
   - Move all mailbox related data to 'struct cxl_mailbox'
   - Refactor mailbox APIs with 'struct cxl_mailbox' as input instead of
     memory device state

  Add support for shared upstream link access_coordinate calculation for
  configurations that have multiple targets under a switch or a root
  port where the aggregated bandwidth can be greater than the upstream
  link of the switch/RP upstream link:
   - Preserve the CDAT access_coordinate from an endpoint
   - Add the support for shared upstream link access_coordinate calculation
   - Add documentation to explain how the calculations are done

  Remove locking from memory notifier callback.

  Misc cleanups:
   - Convert devm_cxl_add_root() to return using ERR_CAST()
   - cxl_test use dev_is_platform() instead of open coding
   - Remove duplicate include of header core.h in core/cdat.c
   - use scoped resource management to drop put_device() for cxl_port
   - Use scoped_guard to drop device_lock() for cxl_port
   - Refactor __devm_cxl_add_port() to drop gotos
   - Rename cxl_setup_parent_dport to cxl_dport_init_aer and
     cxl_dport_map_regs() to cxl_dport_map_ras()
   - Refactor cxl_dport_init_aer() to be more concise
   - Remove duplicate host_bridge->native_aer checking in
     cxl_dport_init_ras_reporting()
   - Fix comment for cxl_query_cmd()"

* tag 'cxl-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (21 commits)
  cxl: Add documentation to explain the shared link bandwidth calculation
  cxl: Calculate region bandwidth of targets with shared upstream link
  cxl: Preserve the CDAT access_coordinate for an endpoint
  cxl: Fix comment regarding cxl_query_cmd() return data
  cxl: Convert cxl_internal_send_cmd() to use 'struct cxl_mailbox' as input
  cxl: Move mailbox related bits to the same context
  cxl: move cxl headers to new include/cxl/ directory
  cxl/region: Remove lock from memory notifier callback
  cxl/pci: simplify the check of mem_enabled in cxl_hdm_decode_init()
  cxl/pci: Check Mem_info_valid bit for each applicable DVSEC
  cxl/pci: Remove duplicated implementation of waiting for memory_info_valid
  cxl/pci: Fix to record only non-zero ranges
  cxl/pci: Remove duplicate host_bridge->native_aer checking
  cxl/pci: cxl_dport_map_rch_aer() cleanup
  cxl/pci: Rename cxl_setup_parent_dport() and cxl_dport_map_regs()
  cxl/port: Refactor __devm_cxl_add_port() to drop goto pattern
  cxl/port: Use scoped_guard()/guard() to drop device_lock() for cxl_port
  cxl/port: Use __free() to drop put_device() for cxl_port
  cxl: Remove duplicate included header file core.h
  tools/testing/cxl: Use dev_is_platform()
  ...