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, 45 insertions, 0 deletions

diff --git a/include/media/i2c/upd64083.h b/include/media/i2c/upd64083.h
new file mode 100644
index 000000000..72cf547c2
--- /dev/null
+++ b/include/media/i2c/upd64083.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * upd6408x - NEC Electronics 3-Dimensional Y/C separation input defines
+ *
+ * 2006 by Hans Verkuil (hverkuil@kernel.org)
+ */
+
+#ifndef _UPD64083_H_
+#define _UPD64083_H_
+
+/* There are two bits of information that the driver needs in order
+   to select the correct routing: the operating mode and the selection
+   of the Y input (external or internal).
+
+   The first two operating modes expect a composite signal on the Y input,
+   the second two operating modes use both the Y and C inputs.
+
+   Normally YCS_MODE is used for tuner and composite inputs, and the
+   YCNR mode is used for S-Video inputs.
+
+   The external Y-ADC is selected when the composite input comes from a
+   upd64031a ghost reduction device. If this device is not present, or
+   the input is a S-Video signal, then the internal Y-ADC input should
+   be used. */
+
+/* Operating modes: */
+
+/* YCS mode: Y/C separation (burst locked clocking) */
+#define UPD64083_YCS_MODE      0
+/* YCS+ mode: 2D Y/C separation and YCNR (burst locked clocking) */
+#define UPD64083_YCS_PLUS_MODE 1
+
+/* Note: the following two modes cannot be used in combination with the
+   external Y-ADC. */
+/* MNNR mode: frame comb type YNR+C delay (line locked clocking) */
+#define UPD64083_MNNR_MODE     2
+/* YCNR mode: frame recursive YCNR (burst locked clocking) */
+#define UPD64083_YCNR_MODE     3
+
+/* Select external Y-ADC: this should be set if this device is used in
+   combination with the upd64031a ghost reduction device.
+   Otherwise leave at 0 (use internal Y-ADC). */
+#define UPD64083_EXT_Y_ADC     (1 << 2)
+
+#endif