[PATCH 5.18 005/181] ALSA: hda: Fix discovery of i915 graphics PCI device

From: Greg Kroah-Hartman
Date: Mon Jun 27 2022 - 07:49:03 EST


From: Takashi Iwai <tiwai@xxxxxxx>

commit 36a38c53b4ee51b90566f8f44a613601eb31a10e upstream.

It's been reported that the recent fix for skipping the
component-binding with D-GPU caused a regression on some systems; it
resulted in the completely missing component binding with i915 GPU.

The problem was the use of pci_get_class() function. It matches with
the full PCI class bits, while we want to match only partially the PCI
base class bits. So, when a system has an i915 graphics device with
the PCI class 0380, it won't hit because we're looking for only the
PCI class 0300.

This patch fixes i915_gfx_present() to look up each PCI device and
match with PCI base class explicitly instead of pci_get_class().

Fixes: c9db8a30d9f0 ("ALSA: hda/i915 - skip acomp init if no matching display")
Reviewed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
Tested-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1200611
Link: https://lore.kernel.org/r/87bkunztec.wl-tiwai@xxxxxxx
Link: https://lore.kernel.org/r/20220621120044.11573-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/hda/hdac_i915.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c
index 3f35972e1cf7..161a9711cd63 100644
--- a/sound/hda/hdac_i915.c
+++ b/sound/hda/hdac_i915.c
@@ -119,21 +119,18 @@ static int i915_component_master_match(struct device *dev, int subcomponent,
/* check whether Intel graphics is present and reachable */
static int i915_gfx_present(struct pci_dev *hdac_pci)
{
- unsigned int class = PCI_BASE_CLASS_DISPLAY << 16;
struct pci_dev *display_dev = NULL;
- bool match = false;

- do {
- display_dev = pci_get_class(class, display_dev);
-
- if (display_dev && display_dev->vendor == PCI_VENDOR_ID_INTEL &&
+ for_each_pci_dev(display_dev) {
+ if (display_dev->vendor == PCI_VENDOR_ID_INTEL &&
+ (display_dev->class >> 16) == PCI_BASE_CLASS_DISPLAY &&
connectivity_check(display_dev, hdac_pci)) {
pci_dev_put(display_dev);
- match = true;
+ return true;
}
- } while (!match && display_dev);
+ }

- return match;
+ return false;
}

/**
--
2.36.1