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, 100 insertions, 0 deletions

diff --git a/drivers/phy/mediatek/Kconfig b/drivers/phy/mediatek/Kconfig
new file mode 100644
index 000000000..ba6461350
--- /dev/null
+++ b/drivers/phy/mediatek/Kconfig
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Mediatek devices
+#
+config PHY_MTK_PCIE
+	tristate "MediaTek PCIe-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek PCIe PHY driver.
+	  This driver create the basic PHY instance and provides initialize
+	  callback for PCIe GEN3 port, it supports software efuse
+	  initialization.
+
+config PHY_MTK_XFI_TPHY
+	tristate "MediaTek 10GE SerDes XFI T-PHY driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek XFI T-PHY driver.
+	  The driver provides access to the Ethernet SerDes T-PHY supporting
+	  1GE and 2.5GE modes via the LynxI PCS, and 5GE and 10GE modes
+	  via the USXGMII PCS found in MediaTek SoCs with 10G Ethernet.
+
+config PHY_MTK_TPHY
+	tristate "MediaTek T-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF && OF_ADDRESS
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek T-PHY driver,
+	  it supports multiple usb2.0, usb3.0 ports, PCIe and
+	  SATA, and meanwhile supports two version T-PHY which have
+	  different banks layout, the T-PHY with shared banks between
+	  multi-ports is first version, otherwise is second version,
+	  so you can easily distinguish them by banks layout.
+
+config PHY_MTK_UFS
+	tristate "MediaTek UFS M-PHY driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Support for UFS M-PHY on MediaTek chipsets.
+	  Enable this to provide vendor-specific probing,
+	  initialization, power on and power off flow of
+	  specified M-PHYs.
+
+config PHY_MTK_XSPHY
+	tristate "MediaTek XS-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF && OF_ADDRESS
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support the SuperSpeedPlus XS-PHY transceiver for
+	  USB3.1 GEN2 controllers on MediaTek chips. The driver supports
+	  multiple USB2.0, USB3.1 GEN2 ports.
+
+config PHY_MTK_HDMI
+	tristate "MediaTek HDMI-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on COMMON_CLK
+	depends on OF
+	depends on REGULATOR
+	select GENERIC_PHY
+	help
+	  Support HDMI PHY for Mediatek SoCs.
+
+config PHY_MTK_MIPI_CSI_0_5
+	tristate "MediaTek MIPI CSI CD-PHY v0.5 Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the MIPI CSI CD-PHY receiver version 0.5.
+	  The driver supports multiple CSI cdphy ports simultaneously.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called phy-mtk-mipi-csi-0-5.
+
+config PHY_MTK_MIPI_DSI
+	tristate "MediaTek MIPI-DSI Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on COMMON_CLK
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Support MIPI DSI for Mediatek SoCs.
+
+config PHY_MTK_DP
+	tristate "MediaTek DP-PHY Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Support DisplayPort PHY for MediaTek SoCs.