x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/hte/Kconfig b/drivers/hte/Kconfig
new file mode 100644
index 000000000..f57bad67d
--- /dev/null
+++ b/drivers/hte/Kconfig
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig HTE
+	bool "Hardware Timestamping Engine (HTE) Support"
+	help
+	  Hardware Timestamping Engine (HTE) Support.
+
+	  Some devices provide a hardware timestamping engine which can
+	  timestamp certain device lines/signals in realtime. It comes with a
+	  benefit for the applications needing accurate timestamping event with
+	  less jitter. This framework provides a generic interface to such HTE
+	  providers and consumer devices.
+
+	  If unsure, say no.
+
+if HTE
+
+config HTE_TEGRA194
+	tristate "NVIDIA Tegra194 HTE Support"
+	depends on (ARCH_TEGRA || COMPILE_TEST)
+	depends on GPIOLIB
+	help
+	  Enable this option for integrated hardware timestamping engine also
+	  known as generic timestamping engine (GTE) support on NVIDIA Tegra194
+	  and later systems-on-chip. The driver supports 352 LIC IRQs and 39
+	  AON GPIOs lines for timestamping in realtime.
+
+config HTE_TEGRA194_TEST
+        tristate "NVIDIA Tegra194 HTE Test"
+        depends on (HTE_TEGRA194 || COMPILE_TEST)
+        help
+	  The NVIDIA Tegra194 GTE test driver demonstrates how to use HTE
+	  framework to timestamp GPIO and LIC IRQ lines.
+
+endif