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From 385f287f9853da402d94278e59f594501c1d1dad Mon Sep 17 00:00:00 2001
From: Libin Yang <libin.yang@intel.com>
Date: Tue, 21 Dec 2021 09:08:16 +0800
Subject: [PATCH] ALSA: hda: intel-sdw-acpi: harden detection of controller
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Git-commit: 385f287f9853da402d94278e59f594501c1d1dad
Patch-mainline: v5.16-rc7
References: git-fixes

The existing code currently sets a pointer to an ACPI handle before
checking that it's actually a SoundWire controller. This can lead to
issues where the graph walk continues and eventually fails, but the
pointer was set already.

This patch changes the logic so that the information provided to
the caller is set when a controller is found.

Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Signed-off-by: Libin Yang <libin.yang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20211221010817.23636-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 sound/hda/intel-sdw-acpi.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sound/hda/intel-sdw-acpi.c b/sound/hda/intel-sdw-acpi.c
index c0123bc31c0d..ba8a872a2901 100644
--- a/sound/hda/intel-sdw-acpi.c
+++ b/sound/hda/intel-sdw-acpi.c
@@ -132,8 +132,6 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
 		return AE_NOT_FOUND;
 	}
 
-	info->handle = handle;
-
 	/*
 	 * On some Intel platforms, multiple children of the HDAS
 	 * device can be found, but only one of them is the SoundWire
@@ -144,6 +142,9 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
 	if (FIELD_GET(GENMASK(31, 28), adr) != SDW_LINK_TYPE)
 		return AE_OK; /* keep going */
 
+	/* found the correct SoundWire controller */
+	info->handle = handle;
+
 	/* device found, stop namespace walk */
 	return AE_CTRL_TERMINATE;
 }
-- 
2.31.1