[PATCH AUTOSEL 6.12 005/107] drm/vc4: hdmi: Increase audio MAI fifo dreq threshold

[Sasha Levin]

From: Dom Cobley <popcornmix at gmail.com>

[ 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 at gmail.com>
Reviewed-by: Maxime Ripard <mripard at kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240621152055.4180873-8-dave.stevenson@raspberrypi.com
Signed-off-by: Dave Stevenson <dave.stevenson at raspberrypi.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 43f4e150d7267..60cbf1d4c7dd1 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2047,6 +2047,7 @@ 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;
@@ -2104,11 +2105,18 @@ 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 |
-- 
2.43.0