[PATCH v2] drm/bridge: dw-hdmi-qp: fix multi-channel audio output

[PATCH v2] drm/bridge: dw-hdmi-qp: fix multi-channel audio output

[Christian Hewitt]

From: Jonas Karlman <jonas@kwiboo.se>

Channel Allocation (PB4) and Level Shift Information (PB5) are
configured with values from PB1 and PB2 due to the wrong offset
being used. This results in missing audio channels or incorrect
speaker placement when playing multi-channel audio.

Use the correct offset to fix multi-channel audio output.

Fixes: fd0141d1a8a2 ("drm/bridge: synopsys: Add audio support for dw-hdmi-qp")
Reported-by: Christian Hewitt <christianshewitt@gmail.com>
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Reviewed-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
Changes in v2:
- Add my SoB as requested in v1 [0]
- Add Cristians review
[0] https://patchwork.kernel.org/project/dri-devel/patch/20251206072718.2039874-1-christianshewitt@gmail.com/

 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
index ab7fed6214e0..facfb7526928 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
@@ -848,7 +848,7 @@ static int dw_hdmi_qp_config_audio_infoframe(struct dw_hdmi_qp *hdmi,
 
 	regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS0, &header_bytes, 1);
 	regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS1, &buffer[3], 1);
-	regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS2, &buffer[4], 1);
+	regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS2, &buffer[7], 1);
 
 	/* Enable ACR, AUDI, AMD */
 	dw_hdmi_qp_mod(hdmi,
-- 
2.43.0

Re: [PATCH v2] drm/bridge: dw-hdmi-qp: fix multi-channel audio output

[Luca Ceresoli]

Hello Christian,

On Sat Feb 28, 2026 at 12:28 PM CET, Christian Hewitt wrote:
> From: Jonas Karlman <jonas@kwiboo.se>
>
> Channel Allocation (PB4) and Level Shift Information (PB5) are
> configured with values from PB1 and PB2 due to the wrong offset
> being used. This results in missing audio channels or incorrect
> speaker placement when playing multi-channel audio.
>
> Use the correct offset to fix multi-channel audio output.
>
> Fixes: fd0141d1a8a2 ("drm/bridge: synopsys: Add audio support for dw-hdmi-qp")
> Reported-by: Christian Hewitt <christianshewitt@gmail.com>
> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
> Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
> Reviewed-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>

While applying this patch to drm-mics-fixes, checkpatch complains:

  -:14: WARNING:BAD_REPORTED_BY_LINK: Reported-by: should be immediately followed by Closes: with a URL to the report

You can send v3 with the link, or just reply with the link and I'll take
care of adding it to the commit message.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v2] drm/bridge: dw-hdmi-qp: fix multi-channel audio output

[Christian Hewitt]

> On 17 Mar 2026, at 8:16 pm, Luca Ceresoli <luca.ceresoli@bootlin.com> wrote:
> 
> Hello Christian,
> 
> On Sat Feb 28, 2026 at 12:28 PM CET, Christian Hewitt wrote:
>> From: Jonas Karlman <jonas@kwiboo.se>
>> 
>> Channel Allocation (PB4) and Level Shift Information (PB5) are
>> configured with values from PB1 and PB2 due to the wrong offset
>> being used. This results in missing audio channels or incorrect
>> speaker placement when playing multi-channel audio.
>> 
>> Use the correct offset to fix multi-channel audio output.
>> 
>> Fixes: fd0141d1a8a2 ("drm/bridge: synopsys: Add audio support for dw-hdmi-qp")
>> Reported-by: Christian Hewitt <christianshewitt@gmail.com>
>> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
>> Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
>> Reviewed-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
> 
> While applying this patch to drm-mics-fixes, checkpatch complains:
> 
>  -:14: WARNING:BAD_REPORTED_BY_LINK: Reported-by: should be immediately followed by Closes: with a URL to the report
> 
> You can send v3 with the link, or just reply with the link and I'll take
> care of adding it to the commit message.

Apologies, it looks like use of Reported-by was tightened since I last
used it, and there’s no official report anywhere I can link to (it was
all done in private channels) so better to just drop it from the v2 patch
if that’s possible? - if not I can send a v3 without it.

Christian

Re: [PATCH v2] drm/bridge: dw-hdmi-qp: fix multi-channel audio output

[Luca Ceresoli]

On Sat, 28 Feb 2026 11:28:22 +0000, Christian Hewitt wrote:
> Channel Allocation (PB4) and Level Shift Information (PB5) are
> configured with values from PB1 and PB2 due to the wrong offset
> being used. This results in missing audio channels or incorrect
> speaker placement when playing multi-channel audio.
> 
> Use the correct offset to fix multi-channel audio output.
> 
> [...]

Applied, thanks!

[1/1] drm/bridge: dw-hdmi-qp: fix multi-channel audio output
      commit: cffcb42c57686e9a801dfcf37a3d0c62e51c1c3e

Best regards,
-- 
Luca Ceresoli <luca.ceresoli@bootlin.com>

Re: [PATCH v2] drm/bridge: dw-hdmi-qp: fix multi-channel audio output

[Luca Ceresoli]

Hello Christian, Cristian, Jonas,

On Tue Mar 17, 2026 at 5:49 PM CET, Christian Hewitt wrote:
>> On 17 Mar 2026, at 8:16 pm, Luca Ceresoli <luca.ceresoli@bootlin.com> wrote:
>>
>> Hello Christian,
>>
>> On Sat Feb 28, 2026 at 12:28 PM CET, Christian Hewitt wrote:
>>> From: Jonas Karlman <jonas@kwiboo.se>
>>>
>>> Channel Allocation (PB4) and Level Shift Information (PB5) are
>>> configured with values from PB1 and PB2 due to the wrong offset
>>> being used. This results in missing audio channels or incorrect
>>> speaker placement when playing multi-channel audio.
>>>
>>> Use the correct offset to fix multi-channel audio output.
>>>
>>> Fixes: fd0141d1a8a2 ("drm/bridge: synopsys: Add audio support for dw-hdmi-qp")
>>> Reported-by: Christian Hewitt <christianshewitt@gmail.com>
>>> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
>>> Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
>>> Reviewed-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
>>
>> While applying this patch to drm-mics-fixes, checkpatch complains:
>>
>>  -:14: WARNING:BAD_REPORTED_BY_LINK: Reported-by: should be immediately followed by Closes: with a URL to the report
>>
>> You can send v3 with the link, or just reply with the link and I'll take
>> care of adding it to the commit message.
>
> Apologies, it looks like use of Reported-by was tightened since I last
> used it, and there’s no official report anywhere I can link to (it was
> all done in private channels) so better to just drop it from the v2 patch
> if that’s possible? - if not I can send a v3 without it.

Thanks for the quick feedback.

I applied keeping the commit message as is. In lack of a public discussion
I guess the 'Reported-by' is somewhat informative anyway. I read the
checkpatch as a general suggestion, not a hard rule.

So now this patch is on drm-misc-fixes, but drm-misc-fixes and
drm-misc-next are now conflicting because of other changes by Cristian
Ciocaltea applied in the meanwhile to drm-misc-next, and particularly
commit 3ea699b56d31 ("drm/bridge: dw-hdmi-qp: Rework Audio InfoFrame
handler").

Cristian, Christian (heh), Jonas, could you please check whether the code
on drm-misc-next has or not the bug that is fixed here? And if it still
has, send a fix based on current drm-misc-next?

Thanks!

Best regards,
Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v2] drm/bridge: dw-hdmi-qp: fix multi-channel audio output

[Cristian Ciocaltea]

Hi Luca,

On 3/17/26 7:35 PM, Luca Ceresoli wrote:
> Hello Christian, Cristian, Jonas,
> 
> On Tue Mar 17, 2026 at 5:49 PM CET, Christian Hewitt wrote:
>>> On 17 Mar 2026, at 8:16 pm, Luca Ceresoli <luca.ceresoli@bootlin.com> wrote:
>>>
>>> Hello Christian,
>>>
>>> On Sat Feb 28, 2026 at 12:28 PM CET, Christian Hewitt wrote:
>>>> From: Jonas Karlman <jonas@kwiboo.se>
>>>>
>>>> Channel Allocation (PB4) and Level Shift Information (PB5) are
>>>> configured with values from PB1 and PB2 due to the wrong offset
>>>> being used. This results in missing audio channels or incorrect
>>>> speaker placement when playing multi-channel audio.
>>>>
>>>> Use the correct offset to fix multi-channel audio output.
>>>>
>>>> Fixes: fd0141d1a8a2 ("drm/bridge: synopsys: Add audio support for dw-hdmi-qp")
>>>> Reported-by: Christian Hewitt <christianshewitt@gmail.com>
>>>> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
>>>> Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
>>>> Reviewed-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
>>>
>>> While applying this patch to drm-mics-fixes, checkpatch complains:
>>>
>>>  -:14: WARNING:BAD_REPORTED_BY_LINK: Reported-by: should be immediately followed by Closes: with a URL to the report
>>>
>>> You can send v3 with the link, or just reply with the link and I'll take
>>> care of adding it to the commit message.
>>
>> Apologies, it looks like use of Reported-by was tightened since I last
>> used it, and there’s no official report anywhere I can link to (it was
>> all done in private channels) so better to just drop it from the v2 patch
>> if that’s possible? - if not I can send a v3 without it.
> 
> Thanks for the quick feedback.
> 
> I applied keeping the commit message as is. In lack of a public discussion
> I guess the 'Reported-by' is somewhat informative anyway. I read the
> checkpatch as a general suggestion, not a hard rule.
> 
> So now this patch is on drm-misc-fixes, but drm-misc-fixes and
> drm-misc-next are now conflicting because of other changes by Cristian
> Ciocaltea applied in the meanwhile to drm-misc-next, and particularly
> commit 3ea699b56d31 ("drm/bridge: dw-hdmi-qp: Rework Audio InfoFrame
> handler").
> 
> Cristian, Christian (heh), Jonas, could you please check whether the code
> on drm-misc-next has or not the bug that is fixed here? And if it still
> has, send a fix based on current drm-misc-next?

The conflicting commit in drm-misc-next (i.e. 3ea699b56d31) implicitly resolves
this audio related issue as well, hence there is no need for any further action.

Regards,
Cristian

Re: [PATCH v2] drm/bridge: dw-hdmi-qp: fix multi-channel audio output

[Luca Ceresoli]

Hello Cristian,

On Wed Mar 18, 2026 at 7:12 PM CET, Cristian Ciocaltea wrote:
>> So now this patch is on drm-misc-fixes, but drm-misc-fixes and
>> drm-misc-next are now conflicting because of other changes by Cristian
>> Ciocaltea applied in the meanwhile to drm-misc-next, and particularly
>> commit 3ea699b56d31 ("drm/bridge: dw-hdmi-qp: Rework Audio InfoFrame
>> handler").
>>
>> Cristian, Christian (heh), Jonas, could you please check whether the code
>> on drm-misc-next has or not the bug that is fixed here? And if it still
>> has, send a fix based on current drm-misc-next?
>
> The conflicting commit in drm-misc-next (i.e. 3ea699b56d31) implicitly resolves
> this audio related issue as well, hence there is no need for any further action.

Good to know! Thanks for checking.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com