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, 30 insertions, 0 deletions

diff --git a/include/drm/drm_utils.h b/include/drm/drm_utils.h
new file mode 100644
index 000000000..7e077484c
--- /dev/null
+++ b/include/drm/drm_utils.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Function prototypes for misc. drm utility functions.
+ * Specifically this file is for function prototypes for functions which
+ * may also be used outside of drm code (e.g. in fbdev drivers).
+ *
+ * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
+ */
+
+#ifndef __DRM_UTILS_H__
+#define __DRM_UTILS_H__
+
+#include <linux/types.h>
+
+struct drm_edid;
+
+int drm_get_panel_orientation_quirk(int width, int height);
+
+struct drm_panel_backlight_quirk {
+	u16 min_brightness;
+	u32 brightness_mask;
+	bool force_pwm;
+};
+
+const struct drm_panel_backlight_quirk *
+drm_get_panel_backlight_quirk(const struct drm_edid *edid);
+
+signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec);
+
+#endif