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, 29 insertions, 0 deletions

diff --git a/sound/last.c b/sound/last.c
new file mode 100644
index 000000000..f0bb98780
--- /dev/null
+++ b/sound/last.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Advanced Linux Sound Architecture
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/init.h>
+#include <sound/core.h>
+
+static int __init alsa_sound_last_init(void)
+{
+	struct snd_card *card;
+	int idx, ok = 0;
+	
+	printk(KERN_INFO "ALSA device list:\n");
+	for (idx = 0; idx < SNDRV_CARDS; idx++) {
+		card = snd_card_ref(idx);
+		if (card) {
+			printk(KERN_INFO "  #%i: %s\n", idx, card->longname);
+			snd_card_unref(card);
+			ok++;
+		}
+	}
+	if (ok == 0)
+		printk(KERN_INFO "  No soundcards found.\n");
+	return 0;
+}
+
+late_initcall_sync(alsa_sound_last_init);