openwrt/target/linux/bcm27xx/patches-5.10/950-0505-vc4-drm-Avoid-full-hdmi-audio-fifo-writes.patch
Álvaro Fernández Rojas 8299d1f057 bcm27xx: add kernel 5.10 support
Rebased RPi foundation patches on linux 5.10.59, removed applied and reverted
patches, wireless patches and defconfig patches.

bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 4B v1.1 4G
bcm2711: boot tested on RPi 4B v1.1 4G

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2021-08-21 19:07:07 +02:00

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1.2 KiB
Diff

From d0df79e13ab947367b86d7861e34f85aa6aad020 Mon Sep 17 00:00:00 2001
From: Dom Cobley <popcornmix@gmail.com>
Date: Sun, 24 Jan 2021 15:44:10 +0000
Subject: [PATCH] vc4/drm: Avoid full hdmi audio fifo writes
We are getting occasional VC4_HD_MAI_CTL_ERRORF in
HDMI_MAI_CTL which seem to correspond with audio dropouts.
Reduce the threshold where we deassert DREQ to avoid the fifo overfilling
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1294,10 +1294,10 @@ static int vc4_hdmi_audio_prepare(struct
/* Set the MAI threshold */
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(0x10, VC4_HD_MAI_THR_DREQHIGH) |
- VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_DREQLOW));
+ 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));
HDMI_WRITE(HDMI_MAI_CONFIG,
VC4_HDMI_MAI_CONFIG_BIT_REVERSE |