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authorÁlvaro Fernández Rojas <noltari@gmail.com>2021-02-18 18:04:33 +0100
committerÁlvaro Fernández Rojas <noltari@gmail.com>2021-02-18 23:42:32 +0100
commitf07e572f6447465d8938679533d604e402b0f066 (patch)
treecb333bd2a67e59e7c07659514850a0fd55fc825e /target/linux/bcm27xx/patches-5.4/950-0895-vc4_hdmi-Remove-firmware-logic-for-MAI-threshold-set.patch
parent5d3a6fd970619dfc55f8259035c3027d7613a2a6 (diff)
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bcm27xx: import latest patches from the RPi foundation
bcm2708: boot tested on RPi B+ v1.2 bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G bcm2710: boot tested on RPi 3B v1.2 bcm2711: boot tested on RPi 4B v1.1 4G Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0895-vc4_hdmi-Remove-firmware-logic-for-MAI-threshold-set.patch')
-rw-r--r--target/linux/bcm27xx/patches-5.4/950-0895-vc4_hdmi-Remove-firmware-logic-for-MAI-threshold-set.patch47
1 files changed, 47 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0895-vc4_hdmi-Remove-firmware-logic-for-MAI-threshold-set.patch b/target/linux/bcm27xx/patches-5.4/950-0895-vc4_hdmi-Remove-firmware-logic-for-MAI-threshold-set.patch
new file mode 100644
index 0000000000..e08ceca15a
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0895-vc4_hdmi-Remove-firmware-logic-for-MAI-threshold-set.patch
@@ -0,0 +1,47 @@
+From 5f22fca663178a49bbb72058ea9225d35b3d155d Mon Sep 17 00:00:00 2001
+From: Dom Cobley <popcornmix@gmail.com>
+Date: Thu, 25 Jun 2020 18:48:40 +0100
+Subject: [PATCH] vc4_hdmi: Remove firmware logic for MAI threshold
+ setting
+
+This was a workaround for bugs in hardware on earlier Pi models
+and wasn't totally successful.
+
+It makes audio quality worse on a Pi4 at the higher sample rates
+
+Signed-off-by: Dom Cobley <popcornmix@gmail.com>
+---
+ drivers/gpu/drm/vc4/vc4_hdmi.c | 22 ++++++----------------
+ 1 file changed, 6 insertions(+), 16 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
++++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
+@@ -1010,22 +1010,12 @@ static int vc4_hdmi_audio_prepare(struct
+ audio_packet_config |= VC4_SET_FIELD(channel_mask,
+ VC4_HDMI_AUDIO_PACKET_CEA_MASK);
+
+- /* Set the MAI threshold. This logic mimics the firmware's. */
+- if (vc4_hdmi->audio.samplerate > 96000) {
+- HDMI_WRITE(HDMI_MAI_THR,
+- VC4_SET_FIELD(0x12, VC4_HD_MAI_THR_DREQHIGH) |
+- VC4_SET_FIELD(0x12, VC4_HD_MAI_THR_DREQLOW));
+- } else if (vc4_hdmi->audio.samplerate > 48000) {
+- HDMI_WRITE(HDMI_MAI_THR,
+- VC4_SET_FIELD(0x14, VC4_HD_MAI_THR_DREQHIGH) |
+- VC4_SET_FIELD(0x12, VC4_HD_MAI_THR_DREQLOW));
+- } else {
+- 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));
+- }
++ /* 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));
+
+ HDMI_WRITE(HDMI_MAI_CONFIG,
+ VC4_HDMI_MAI_CONFIG_BIT_REVERSE |