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, 92 insertions, 0 deletions

diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
new file mode 100644
index 000000000..d7293977f
--- /dev/null
+++ b/drivers/soc/mediatek/Kconfig
@@ -0,0 +1,92 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# MediaTek SoC drivers
+#
+menu "MediaTek SoC drivers"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+
+config MTK_CMDQ
+	tristate "MediaTek CMDQ Support"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	select MAILBOX
+	select MTK_CMDQ_MBOX
+	select MTK_INFRACFG
+	help
+	  Say yes here to add support for the MediaTek Command Queue (CMDQ)
+	  driver. The CMDQ is used to help read/write registers with critical
+	  time limitation, such as updating display configuration during the
+	  vblank.
+
+config MTK_DEVAPC
+	tristate "Mediatek Device APC Support"
+	help
+	  Say yes here to enable support for Mediatek Device APC driver.
+	  This driver is mainly used to handle the violation which catches
+	  unexpected transaction.
+	  The violation information is logged for further analysis or
+	  countermeasures.
+
+config MTK_DVFSRC
+	tristate "MediaTek DVFSRC Support"
+	depends on ARCH_MEDIATEK
+	help
+	  Say yes here to add support for the MediaTek Dynamic Voltage
+	  and Frequency Scaling Resource Collector (DVFSRC): a HW
+	  IP found on many MediaTek SoCs, which is responsible for
+	  collecting DVFS requests from various SoC IPs, other than
+	  software, and performing bandwidth scaling to provide the
+	  best achievable performance-per-watt.
+
+config MTK_INFRACFG
+	bool "MediaTek INFRACFG Support"
+	select REGMAP
+	help
+	  Say yes here to add support for the MediaTek INFRACFG controller. The
+	  INFRACFG controller contains various infrastructure registers not
+	  directly associated to any device.
+
+config MTK_PMIC_WRAP
+	tristate "MediaTek PMIC Wrapper Support"
+	depends on RESET_CONTROLLER
+	depends on OF
+	select REGMAP
+	help
+	  Say yes here to add support for MediaTek PMIC Wrapper found
+	  on different MediaTek SoCs. The PMIC wrapper is a proprietary
+	  hardware to connect the PMIC.
+
+config MTK_REGULATOR_COUPLER
+	bool "MediaTek SoC Regulator Coupler" if COMPILE_TEST
+	default ARCH_MEDIATEK
+	depends on REGULATOR
+
+config MTK_MMSYS
+	tristate "MediaTek MMSYS Support"
+	default ARCH_MEDIATEK
+	depends on HAS_IOMEM
+	depends on MTK_CMDQ || MTK_CMDQ=n
+	help
+	  Say yes here to add support for the MediaTek Multimedia
+	  Subsystem (MMSYS).
+
+config MTK_SVS
+	tristate "MediaTek Smart Voltage Scaling(SVS)"
+	depends on NVMEM_MTK_EFUSE && NVMEM
+	help
+	  The Smart Voltage Scaling(SVS) engine is a piece of hardware
+	  which has several controllers(banks) for calculating suitable
+	  voltage to different power domains(CPU/GPU/CCI) according to
+	  chip process corner, temperatures and other factors. Then DVFS
+	  driver could apply SVS bank voltage to PMIC/Buck.
+
+config MTK_SOCINFO
+	tristate "MediaTek SoC Information"
+	default y
+	depends on NVMEM_MTK_EFUSE
+	select SOC_BUS
+	help
+	  The MediaTek SoC Information (mtk-socinfo) driver provides
+	  information about the SoC to the userspace including the
+	  manufacturer name, marketing name and soc name.
+
+endmenu