Currently i915_component_master_match() will return the first matching
i915 instance. This does not work in case system has multiple i915
and HDA audio controller instances.
Add a new connectivity check that handles following cases:
- i915 and HDA controller on same PCI bus
- discrete GPU with embedded HDA audio controller connected
via PCI bridge
Signed-off-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
---
sound/hda/hdac_i915.c | 44 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 42 insertions(+), 2 deletions(-)
diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c
index 3c2db3816029..50b2c1db429b 100644
--- a/sound/hda/hdac_i915.c
+++ b/sound/hda/hdac_i915.c
@@ -73,11 +73,51 @@ void snd_hdac_i915_set_bclk(struct hdac_bus *bus)
}
EXPORT_SYMBOL_GPL(snd_hdac_i915_set_bclk);
+/**
+ * Returns true if the devices can be connected for audio.
+ */
+static bool connectivity_check(struct pci_dev *i915, struct pci_dev *hdac)
+{
+ struct pci_bus *bus_a = i915->bus, *bus_b = hdac->bus;
+
+ /* directly connected on the same bus */
+ if (bus_a == bus_b)
+ return true;
+
+ /*
+ * on i915 discrete GPUs with embedded HDA audio, the two
+ * devices are connected via 2nd level PCI bridge
+ */
+ bus_a = bus_a->parent;
+ bus_b = bus_b->parent;
+ if (!bus_a || !bus_b)
+ return false;
+ bus_a = bus_a->parent;
+ bus_b = bus_b->parent;
+ if (bus_a && bus_a == bus_b)
+ return true;
+
+ return false;
+}
+
static int i915_component_master_match(struct device *dev, int subcomponent,
void *data)
{
- return !strcmp(dev->driver->name, "i915") &&
- subcomponent == I915_COMPONENT_AUDIO;
+ struct pci_dev *hdac_pci, *i915_pci;
+ struct hdac_bus *bus = data;
+
+ if (!dev_is_pci(dev))
+ return 0;
+
+ hdac_pci = to_pci_dev(bus->dev);
+ i915_pci = to_pci_dev(dev);
+
+ if (!strcmp(dev->driver->name, "i915") &&
+ subcomponent == I915_COMPONENT_AUDIO &&
+ connectivity_check(i915_pci, hdac_pci))
+ return 1;
+
+ return 0;
}
/* check whether intel graphics is present */
--
2.27.0
