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, 37 insertions, 0 deletions

diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
new file mode 100644
index 000000000..494ab0377
--- /dev/null
+++ b/drivers/usb/misc/Makefile
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the rest of the USB drivers
+# (the ones that don't fit into any other categories)
+#
+obj-$(CONFIG_USB_ADUTUX)		+= adutux.o
+obj-$(CONFIG_USB_APPLEDISPLAY)		+= appledisplay.o
+obj-$(CONFIG_USB_CYPRESS_CY7C63)	+= cypress_cy7c63.o
+obj-$(CONFIG_USB_CYTHERM)		+= cytherm.o
+obj-$(CONFIG_USB_EMI26)			+= emi26.o
+obj-$(CONFIG_USB_EMI62)			+= emi62.o
+obj-$(CONFIG_USB_EZUSB_FX2)		+= ezusb.o
+obj-$(CONFIG_APPLE_MFI_FASTCHARGE)	+= apple-mfi-fastcharge.o
+obj-$(CONFIG_USB_LJCA)			+= usb-ljca.o
+obj-$(CONFIG_USB_USBIO)			+= usbio.o
+obj-$(CONFIG_USB_IDMOUSE)		+= idmouse.o
+obj-$(CONFIG_USB_IOWARRIOR)		+= iowarrior.o
+obj-$(CONFIG_USB_ISIGHTFW)		+= isight_firmware.o
+obj-$(CONFIG_USB_LCD)			+= usblcd.o
+obj-$(CONFIG_USB_LD)			+= ldusb.o
+obj-$(CONFIG_USB_LEGOTOWER)		+= legousbtower.o
+obj-$(CONFIG_USB_QCOM_EUD)		+= qcom_eud.o
+obj-$(CONFIG_USB_TEST)			+= usbtest.o
+obj-$(CONFIG_USB_EHSET_TEST_FIXTURE)    += ehset.o
+obj-$(CONFIG_USB_TRANCEVIBRATOR)	+= trancevibrator.o
+obj-$(CONFIG_USB_USS720)		+= uss720.o
+obj-$(CONFIG_USB_SEVSEG)		+= usbsevseg.o
+obj-$(CONFIG_USB_YUREX)			+= yurex.o
+obj-$(CONFIG_USB_HUB_USB251XB)		+= usb251xb.o
+obj-$(CONFIG_USB_HSIC_USB3503)		+= usb3503.o
+obj-$(CONFIG_USB_HSIC_USB4604)		+= usb4604.o
+obj-$(CONFIG_USB_CHAOSKEY)		+= chaoskey.o
+
+obj-$(CONFIG_USB_SISUSBVGA)		+= sisusbvga/
+obj-$(CONFIG_USB_LINK_LAYER_TEST)	+= lvstest.o
+obj-$(CONFIG_BRCM_USB_PINMAP)		+= brcmstb-usb-pinmap.o
+obj-$(CONFIG_USB_ONBOARD_DEV)		+= onboard_usb_dev.o