Re: Regression: Kernel 4.6 DisplayPort Audio

From: Takashi Iwai
Date: Wed May 11 2016 - 09:09:29 EST


On Wed, 11 May 2016 14:52:22 +0200,
Daniel Exner wrote:
>
> Hi,
>
> Am 11.05.2016 um 10:48 schrieb Takashi Iwai:
> [..]
>
> > If the commit above alone breaks, does the patch below change the
> > behavior? Through a quick look at it, some ops are overridden only
> > conditionally while the older code always overwrote them.
>
> Yes, the patch fixes it. Thanks!
> I hope its possible to include that in 4.6.

Good to hear!
FWIW, below is the proper patch I'm going to queue.


thanks,

Takashi

-- 8< --
From: Takashi Iwai <tiwai@xxxxxxx>
Subject: [PATCH] ALSA: hda - Fix regression on ATI HDMI audio

The HDMI/DP audio output on ATI/AMD chips got broken due to the recent
restructuring of chmap. Fortunately, Daniel Exner could bisect, and
pointed the culprit commit [739ffee97ed5: ALSA: hda - Add hdmi chmap
verb programming ops to chmap object].

This commit moved some ops from hdmi_ops to chmap_ops, and reassigned
the ops in the embedded chmap object in hdmi_spec instead.
Unfortunately, the reassignment of these ops in patch_atihdmi() were
moved into an if block that is performed only for old chips. Thus, on
newer chips, the generic ops is still used, which doesn't work for
such ATI/AMD chips.

This patch addresses the regression, simply by moving the assignment
of chmap ops to the right place.

Fixes: 739ffee97ed5 ('ALSA: hda - Add hdmi chmap verb programming ops to chmap object')
Reported-and-tested-by: Daniel Exner <dex@xxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/pci/hda/patch_hdmi.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 1483f85999ec..a010d704e0e2 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -3401,6 +3401,9 @@ static int patch_atihdmi(struct hda_codec *codec)
spec->ops.pin_hbr_setup = atihdmi_pin_hbr_setup;
spec->ops.setup_stream = atihdmi_setup_stream;

+ spec->chmap.ops.pin_get_slot_channel = atihdmi_pin_get_slot_channel;
+ spec->chmap.ops.pin_set_slot_channel = atihdmi_pin_set_slot_channel;
+
if (!has_amd_full_remap_support(codec)) {
/* override to ATI/AMD-specific versions with pairwise mapping */
spec->chmap.ops.chmap_cea_alloc_validate_get_type =
@@ -3408,10 +3411,6 @@ static int patch_atihdmi(struct hda_codec *codec)
spec->chmap.ops.cea_alloc_to_tlv_chmap =
atihdmi_paired_cea_alloc_to_tlv_chmap;
spec->chmap.ops.chmap_validate = atihdmi_paired_chmap_validate;
- spec->chmap.ops.pin_get_slot_channel =
- atihdmi_pin_get_slot_channel;
- spec->chmap.ops.pin_set_slot_channel =
- atihdmi_pin_set_slot_channel;
}

/* ATI/AMD converters do not advertise all of their capabilities */
--
2.8.2