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Diffstat (limited to 'drivers/soundwire/intel_init.c')
-rw-r--r--drivers/soundwire/intel_init.c25
1 files changed, 24 insertions, 1 deletions
diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c
index d3d6b54c5791..70637a0383d2 100644
--- a/drivers/soundwire/intel_init.c
+++ b/drivers/soundwire/intel_init.c
@@ -14,6 +14,7 @@
#include <linux/soundwire/sdw_intel.h>
#include "intel.h"
+#define SDW_LINK_TYPE 4 /* from Intel ACPI documentation */
#define SDW_MAX_LINKS 4
#define SDW_SHIM_LCAP 0x0
#define SDW_SHIM_BASE 0x2C000
@@ -80,6 +81,7 @@ static struct sdw_intel_ctx
/* Check SNDWLCAP.LCOUNT */
caps = ioread32(res->mmio_base + SDW_SHIM_BASE + SDW_SHIM_LCAP);
+ caps &= GENMASK(2, 0);
/* Check HW supported vs property value and use min of two */
count = min_t(u8, caps, count);
@@ -89,6 +91,9 @@ static struct sdw_intel_ctx
dev_err(&adev->dev, "Link count %d exceeds max %d\n",
count, SDW_MAX_LINKS);
return NULL;
+ } else if (!count) {
+ dev_warn(&adev->dev, "No SoundWire links detected\n");
+ return NULL;
}
dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);
@@ -150,6 +155,12 @@ 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 +168,19 @@ 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), with bits 31..28 representing the
+ * SoundWire link so filter accordingly
+ */
+ if ((adr & GENMASK(31, 28)) >> 28 != SDW_LINK_TYPE)
+ return AE_OK; /* keep going */
+
+ /* device found, stop namespace walk */
+ return AE_CTRL_TERMINATE;
}
/**