[alsa-devel] [PATCH 1/8] soundwire: intel: filter SoundWire controller device search
Pierre-Louis Bossart
pierre-louis.bossart at linux.intel.com
Sat May 4 02:29:19 CEST 2019
The convention is that the SoundWire controller device is a child of
the HDAudio controller. However there can be more than one child
exposed in the DSDT table, and the current namespace walk returns the
last device.
Add a filter and terminate early when a valid _ADR is provided,
otherwise keep iterating to find the next child.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
drivers/soundwire/intel_init.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c
index d3d6b54c5791..f85db67d05f0 100644
--- a/drivers/soundwire/intel_init.c
+++ b/drivers/soundwire/intel_init.c
@@ -150,6 +150,12 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
{
struct sdw_intel_res *res = cdata;
struct acpi_device *adev;
+ acpi_status status;
+ u64 adr;
+
+ status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
+ if (ACPI_FAILURE(status))
+ return AE_OK; /* keep going */
if (acpi_bus_get_device(handle, &adev)) {
pr_err("%s: Couldn't find ACPI handle\n", __func__);
@@ -157,7 +163,18 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
}
res->handle = handle;
- return AE_OK;
+
+ /*
+ * On some Intel platforms, multiple children of the HDAS
+ * device can be found, but only one of them is the SoundWire
+ * controller. The SNDW device is always exposed with
+ * Name(_ADR, 0x40000000) so filter accordingly
+ */
+ if (adr != 0x40000000)
+ return AE_OK; /* keep going */
+
+ /* device found, stop namespace walk */
+ return AE_CTRL_TERMINATE;
}
/**
--
2.17.1
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