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, 95 insertions, 0 deletions

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
new file mode 100644
index 000000000..a7144d275
--- /dev/null
+++ b/drivers/video/Kconfig
@@ -0,0 +1,95 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Video configuration
+#
+
+menu "Graphics support"
+
+config APERTURE_HELPERS
+	bool
+	help
+	  Support tracking and hand-over of aperture ownership. Required
+	  by graphics drivers for firmware-provided framebuffers.
+
+config SCREEN_INFO
+	bool
+	default n
+
+config STI_CORE
+	bool
+	depends on PARISC
+	help
+	  STI refers to the HP "Standard Text Interface" which is a set of
+	  BIOS routines contained in a ROM chip in HP PA-RISC based machines.
+
+config VIDEO
+	bool
+	default n
+
+source "drivers/auxdisplay/Kconfig"
+
+if HAS_IOMEM
+
+config HAVE_FB_ATMEL
+	bool
+
+source "drivers/char/agp/Kconfig"
+
+source "drivers/gpu/vga/Kconfig"
+
+source "drivers/gpu/Kconfig"
+source "drivers/gpu/host1x/Kconfig"
+source "drivers/gpu/ipu-v3/Kconfig"
+source "drivers/gpu/nova-core/Kconfig"
+
+source "drivers/gpu/drm/Kconfig"
+
+menu "Frame buffer Devices"
+source "drivers/video/fbdev/Kconfig"
+endmenu
+
+source "drivers/video/backlight/Kconfig"
+
+config VGASTATE
+       tristate
+       default n
+
+config VIDEOMODE_HELPERS
+	bool
+
+config HDMI
+	bool
+
+endif # HAS_IOMEM
+
+config FIRMWARE_EDID
+	bool "Enable firmware EDID"
+	depends on EFI_GENERIC_STUB || X86
+	help
+	  This enables access to the EDID transferred from the firmware.
+	  On EFI systems, the EDID comes from the same device as the
+	  primary GOP. On x86 with BIOS, it comes from the VESA BIOS.
+	  DRM display drivers will be able to export the information
+	  to userspace.
+
+	  Also enable this if DDC/I2C transfers do not work for your driver
+	  and if you are using nvidiafb, i810fb or savagefb.
+
+	  In general, choosing Y for this option is safe.  If you
+	  experience extremely long delays while booting before you get
+	  something on your display, try setting this to N.  Matrox cards in
+	  combination with certain motherboards and monitors are known to
+	  suffer from this problem.
+
+if VT
+	source "drivers/video/console/Kconfig"
+endif
+
+if FB_CORE || SGI_NEWPORT_CONSOLE
+	source "drivers/video/logo/Kconfig"
+
+endif
+
+source "drivers/gpu/trace/Kconfig"
+
+endmenu