This is a note to let you know that I've just added the patch titled
drm/vc4: hdmi: Increase audio MAI fifo dreq threshold
to the 6.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-vc4-hdmi-increase-audio-mai-fifo-dreq-threshold.patch
and it can be found in the queue-6.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8afa5b53e9881683b5c245a9c0083d12c7d4d99a
Author: Dom Cobley <popcornmix@xxxxxxxxx>
Date: Fri Jun 21 16:20:31 2024 +0100
drm/vc4: hdmi: Increase audio MAI fifo dreq threshold
[ Upstream commit 59f8b2b7fb8e460881d21c7d5b32604993973879 ]
Now we wait for write responses and have a burst
size of 4, we can set the fifo threshold much higher.
Set it to 28 (of the 32 entry size) to keep fifo
fuller and reduce chance of underflow.
Signed-off-by: Dom Cobley <popcornmix@xxxxxxxxx>
Reviewed-by: Maxime Ripard <mripard@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240621152055.4180873-8-dave.stevenson@xxxxxxxxxxxxxxx
Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
Stable-dep-of: cf1c87d978d4 ("drm/vc4: Match drm_dev_enter and exit calls in vc4_hvs_lut_load")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 6c2215068c537..0117c5495b893 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2051,6 +2051,7 @@ static int vc4_hdmi_audio_prepare(struct device *dev, void *data,
struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
struct drm_device *drm = vc4_hdmi->connector.dev;
struct drm_connector *connector = &vc4_hdmi->connector;
+ struct vc4_dev *vc4 = to_vc4_dev(drm);
unsigned int sample_rate = params->sample_rate;
unsigned int channels = params->channels;
unsigned long flags;
@@ -2108,11 +2109,18 @@ static int vc4_hdmi_audio_prepare(struct device *dev, void *data,
VC4_HDMI_AUDIO_PACKET_CEA_MASK);
/* Set the MAI threshold */
- HDMI_WRITE(HDMI_MAI_THR,
- VC4_SET_FIELD(0x08, VC4_HD_MAI_THR_PANICHIGH) |
- VC4_SET_FIELD(0x08, VC4_HD_MAI_THR_PANICLOW) |
- VC4_SET_FIELD(0x06, VC4_HD_MAI_THR_DREQHIGH) |
- VC4_SET_FIELD(0x08, VC4_HD_MAI_THR_DREQLOW));
+ if (vc4->is_vc5)
+ HDMI_WRITE(HDMI_MAI_THR,
+ VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_PANICHIGH) |
+ VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_PANICLOW) |
+ VC4_SET_FIELD(0x1c, VC4_HD_MAI_THR_DREQHIGH) |
+ VC4_SET_FIELD(0x1c, VC4_HD_MAI_THR_DREQLOW));
+ else
+ HDMI_WRITE(HDMI_MAI_THR,
+ VC4_SET_FIELD(0x8, VC4_HD_MAI_THR_PANICHIGH) |
+ VC4_SET_FIELD(0x8, VC4_HD_MAI_THR_PANICLOW) |
+ VC4_SET_FIELD(0x6, VC4_HD_MAI_THR_DREQHIGH) |
+ VC4_SET_FIELD(0x8, VC4_HD_MAI_THR_DREQLOW));
HDMI_WRITE(HDMI_MAI_CONFIG,
VC4_HDMI_MAI_CONFIG_BIT_REVERSE |
