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, 68 insertions, 0 deletions

diff --git a/drivers/gnss/Kconfig b/drivers/gnss/Kconfig
new file mode 100644
index 000000000..d7fe265c2
--- /dev/null
+++ b/drivers/gnss/Kconfig
@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# GNSS receiver configuration
+#
+
+menuconfig GNSS
+	tristate "GNSS receiver support"
+	help
+	  Say Y here if you have a GNSS receiver (e.g. a GPS receiver).
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called gnss.
+
+if GNSS
+
+config GNSS_SERIAL
+	tristate
+
+config GNSS_MTK_SERIAL
+	tristate "Mediatek GNSS receiver support"
+	depends on SERIAL_DEV_BUS
+	select GNSS_SERIAL
+	help
+	  Say Y here if you have a Mediatek-based GNSS receiver which uses a
+	  serial interface.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called gnss-mtk.
+
+	  If unsure, say N.
+
+config GNSS_SIRF_SERIAL
+	tristate "SiRFstar GNSS receiver support"
+	depends on SERIAL_DEV_BUS
+	help
+	  Say Y here if you have a SiRFstar-based GNSS receiver which uses a
+	  serial interface.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called gnss-sirf.
+
+	  If unsure, say N.
+
+config GNSS_UBX_SERIAL
+	tristate "u-blox GNSS receiver support"
+	depends on SERIAL_DEV_BUS
+	select GNSS_SERIAL
+	help
+	  Say Y here if you have a u-blox GNSS receiver which uses a serial
+	  interface.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called gnss-ubx.
+
+	  If unsure, say N.
+
+config GNSS_USB
+	tristate "USB GNSS receiver support"
+	depends on USB
+	help
+	  Say Y here if you have a GNSS receiver which uses a USB interface.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called gnss-usb.
+
+	  If unsure, say N.
+
+endif # GNSS