drm/vc4: hdmi: Increase audio MAI fifo dreq threshold

BugLink: https://bugs.launchpad.net/bugs/2101915

[ 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@gmail.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240621152055.4180873-8-dave.stevenson@raspberrypi.com
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Stable-dep-of: cf1c87d978d4 ("drm/vc4: Match drm_dev_enter and exit calls in vc4_hvs_lut_load")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[koichiroden: adjusted context due to missing commit:
b47a72f30768 ("drm/vc4: hdmi: Switch to HDMI connector")]
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
This commit is contained in:
Dom Cobley
2025-03-11 08:51:19 +09:00
committed by Stefan Bader
parent e6ef0b5463
commit 00f01d1db9
+13 -5
View File
@@ -2534,6 +2534,7 @@ 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_encoder *encoder = &vc4_hdmi->encoder.base;
struct vc4_dev *vc4 = to_vc4_dev(drm);
unsigned int sample_rate = params->sample_rate;
unsigned int channels = params->channels;
unsigned long flags;
@@ -2591,11 +2592,18 @@ 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 |