-----Original Message-----
From: Intel-wired-lan <redacted> On Behalf
Of Ivan Vecera
Sent: Friday, January 30, 2026 5:54 PM
To: netdev@vger.kernel.org
Cc: Eric Dumazet <edumazet@google.com>; Nguyen, Anthony L
[off-list ref]; Leon Romanovsky [off-list ref];
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Subject: [Intel-wired-lan] [PATCH net-next v3 7/9] dpll: Add reference
count tracking support

Add support for the REF_TRACKER infrastructure to the DPLL subsystem.

When enabled, this allows developers to track and debug reference
counting leaks or imbalances for dpll_device and dpll_pin objects. It
records stack traces for every get/put operation and exposes this
information via debugfs at:
  /sys/kernel/debug/ref_tracker/dpll_device_*
  /sys/kernel/debug/ref_tracker/dpll_pin_*

The following API changes are made to support this:
1. dpll_device_get() / dpll_device_put() now accept a 'dpll_tracker *'
   (which is a typedef to 'struct ref_tracker *' when enabled, or an
empty
   struct otherwise).
2. dpll_pin_get() / dpll_pin_put() and fwnode_dpll_pin_find()
similarly
   accept the tracker argument.
3. Internal registration structures now hold a tracker to associate
the
   reference held by the registration with the specific owner.

All existing in-tree drivers (ice, mlx5, ptp_ocp, zl3073x) are updated
to pass NULL for the new tracker argument, maintaining current
behavior while enabling future debugging capabilities.

Co-developed-by: Petr Oros <redacted>
Signed-off-by: Petr Oros <redacted>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
v3:
* added Kconfig dependency on STACKTRACE_SUPPORT and DEBUG_KERNEL
---
 drivers/dpll/Kconfig                          | 15 +++
 drivers/dpll/dpll_core.c                      | 98 ++++++++++++++----
-
 drivers/dpll/dpll_core.h                      |  5 +
 drivers/dpll/zl3073x/dpll.c                   | 12 +--
 drivers/net/ethernet/intel/ice/ice_dpll.c     | 14 +--
 .../net/ethernet/mellanox/mlx5/core/dpll.c    | 13 +--
 drivers/ptp/ptp_ocp.c                         | 15 +--
 include/linux/dpll.h                          | 19 +++-
 8 files changed, 138 insertions(+), 53 deletions(-)

diff --git a/drivers/dpll/Kconfig b/drivers/dpll/Kconfig index

ade872c915ac6..be98969f040ab 100644

--- a/drivers/dpll/Kconfig
+++ b/drivers/dpll/Kconfig

@@ -8,6 +8,21 @@ menu "DPLL device support"
 config DPLL
 	bool

+config DPLL_REFCNT_TRACKER
+	bool "DPLL reference count tracking"
+	depends on DEBUG_KERNEL && STACKTRACE_SUPPORT && DPLL
+	select REF_TRACKER
+	help
+	  Enable reference count tracking for DPLL devices and pins.
+	  This helps debugging reference leaks and use-after-free bugs
+	  by recording stack traces for each get/put operation.
+
+	  The tracking information is exposed via debugfs at:
+	    /sys/kernel/debug/ref_tracker/dpll_device_*
+	    /sys/kernel/debug/ref_tracker/dpll_pin_*
+
+	  If unsure, say N.
+
 source "drivers/dpll/zl3073x/Kconfig"

 endmenu

diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c index

33333bc2f0cc8..52b2398b9f3ec 100644