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ALSA: hda - handle multiple i915 device instances 

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@linux.intel.com>
Link: https://lore.kernel.org/r/20200921141741.2983072-4-kai.vehmanen@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Kai Vehmanen 2020-09-21 17:17:40 +03:00 committed by Takashi Iwai
parent 1bee263dfd
commit 7b882fe3e3
1 changed files with 42 additions and 2 deletions
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44
sound/hda/hdac_i915.c
View File

@ -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 */