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, 49 insertions, 0 deletions

diff --git a/include/sound/sdw.h b/include/sound/sdw.h
new file mode 100644
index 000000000..6dcdb3228
--- /dev/null
+++ b/include/sound/sdw.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * linux/sound/sdw.h -- SoundWire helpers for ALSA/ASoC
+ *
+ * Copyright (c) 2022 Cirrus Logic Inc.
+ *
+ * Author: Charles Keepax <ckeepax@opensource.cirrus.com>
+ */
+
+#include <linux/soundwire/sdw.h>
+#include <sound/asound.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+
+#ifndef __INCLUDE_SOUND_SDW_H
+#define __INCLUDE_SOUND_SDW_H
+
+/**
+ * snd_sdw_params_to_config() - Conversion from hw_params to SoundWire config
+ *
+ * @substream: Pointer to the PCM substream structure
+ * @params: Pointer to the hardware params structure
+ * @stream_config: Stream configuration for the SoundWire audio stream
+ * @port_config: Port configuration for the SoundWire audio stream
+ *
+ * This function provides a basic conversion from the hw_params structure to
+ * SoundWire configuration structures. The user will at a minimum need to also
+ * set the port number in the port config, but may also override more of the
+ * setup, or in the case of a complex user, not use this helper at all and
+ * open-code everything.
+ */
+static inline void snd_sdw_params_to_config(struct snd_pcm_substream *substream,
+					    struct snd_pcm_hw_params *params,
+					    struct sdw_stream_config *stream_config,
+					    struct sdw_port_config *port_config)
+{
+	stream_config->frame_rate = params_rate(params);
+	stream_config->ch_count = params_channels(params);
+	stream_config->bps = snd_pcm_format_width(params_format(params));
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		stream_config->direction = SDW_DATA_DIR_RX;
+	else
+		stream_config->direction = SDW_DATA_DIR_TX;
+
+	port_config->ch_mask = GENMASK(stream_config->ch_count - 1, 0);
+}
+
+#endif