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, 42 insertions, 0 deletions

diff --git a/include/sound/intel-dsp-config.h b/include/sound/intel-dsp-config.h
new file mode 100644
index 000000000..34c975910
--- /dev/null
+++ b/include/sound/intel-dsp-config.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  intel-dsp-config.h - Intel DSP config
+ *
+ *  Copyright (c) 2019 Jaroslav Kysela <perex@perex.cz>
+ */
+
+#ifndef __INTEL_DSP_CONFIG_H__
+#define __INTEL_DSP_CONFIG_H__
+
+struct pci_dev;
+
+enum {
+	SND_INTEL_DSP_DRIVER_ANY = 0,
+	SND_INTEL_DSP_DRIVER_LEGACY,
+	SND_INTEL_DSP_DRIVER_SST,
+	SND_INTEL_DSP_DRIVER_SOF,
+	SND_INTEL_DSP_DRIVER_AVS,
+	SND_INTEL_DSP_DRIVER_LAST = SND_INTEL_DSP_DRIVER_AVS
+};
+
+#if IS_ENABLED(CONFIG_SND_INTEL_DSP_CONFIG)
+
+int snd_intel_dsp_driver_probe(struct pci_dev *pci);
+int snd_intel_acpi_dsp_driver_probe(struct device *dev, const u8 acpi_hid[ACPI_ID_LEN]);
+
+#else
+
+static inline int snd_intel_dsp_driver_probe(struct pci_dev *pci)
+{
+	return SND_INTEL_DSP_DRIVER_ANY;
+}
+
+static inline
+int snd_intel_acpi_dsp_driver_probe(struct device *dev, const u8 acpi_hid[ACPI_ID_LEN])
+{
+	return SND_INTEL_DSP_DRIVER_ANY;
+}
+
+#endif
+
+#endif