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, 33 insertions, 0 deletions

diff --git a/drivers/misc/cardreader/Kconfig b/drivers/misc/cardreader/Kconfig
new file mode 100644
index 000000000..a70700f0e
--- /dev/null
+++ b/drivers/misc/cardreader/Kconfig
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config MISC_ALCOR_PCI
+	tristate "Alcor Micro/Alcor Link PCI-E card reader"
+	depends on PCI
+	select MFD_CORE
+	help
+	  This supports for Alcor Micro PCI-Express card reader including au6601,
+	  au6621.
+	  Alcor Micro card readers support access to many types of memory cards,
+	  such as Memory Stick, Memory Stick Pro, Secure Digital and
+	  MultiMediaCard.
+
+config MISC_RTSX_PCI
+	tristate "Realtek PCI-E card reader"
+	depends on PCI
+	select MFD_CORE
+	help
+	  This supports for Realtek PCI-Express card reader including rts5209,
+	  rts5227, rts5228, rts522A, rts5229, rts5249, rts524A, rts525A, rtl8411,
+	  rts5260, rts5261, rts5264.
+	  Realtek card readers support access to many types of memory cards,
+	  such as Memory Stick, Memory Stick Pro, Secure Digital and
+	  MultiMediaCard.
+
+config MISC_RTSX_USB
+	tristate "Realtek USB card reader"
+	depends on USB
+	select MFD_CORE
+	help
+	  Select this option to get support for Realtek USB 2.0 card readers
+	  including RTS5129, RTS5139, RTS5179 and RTS5170.
+	  Realtek card reader supports access to many types of memory cards,
+	  such as Memory Stick Pro, Secure Digital and MultiMediaCard.