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authorDom Cobley <popcornmix@gmail.com>2021-05-25 15:23:48 +0200
committerMaxime Ripard <maxime@cerno.tech>2021-06-23 14:32:27 +0200
commit1698ecb218eb82587dbfc71a2e26ded66e5ecf59 (patch)
tree48771977eb946bff77922881c888d654a8ad02f8 /drivers/gpu/drm/vc4
parentecd3ee3d0c734b9454fc59cbe268c6be26f369e8 (diff)
downloadlinux-1698ecb218eb82587dbfc71a2e26ded66e5ecf59.tar.bz2
drm/vc4: hdmi: Set HD_CTL_WHOLSMP and HD_CTL_CHALIGN_SET
Symptom is random switching of speakers when using multichannel. Repeatedly running speakertest -c8 occasionally starts with channels jumbled. This is fixed with HD_CTL_WHOLSMP. The other bit looks beneficial and apears harmless in testing so I'd suggest adding it too. Documentation says: HD_CTL_WHILSMP_SET Wait for whole sample. When this bit is set MAI transmit will start only when there is at least one whole sample available in the fifo. Documentation says: HD_CTL_CHALIGN_SET Channel Align When Overflow. This bit is used to realign the audio channels in case of an overflow. If this bit is set, after the detection of an overflow, equal amount of dummy words to the missing words will be written to fifo, filling up the broken sample and maintaining alignment. Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org> Link: https://patchwork.freedesktop.org/patch/msgid/20210525132354.297468-7-maxime@cerno.tech
Diffstat (limited to 'drivers/gpu/drm/vc4')
-rw-r--r--drivers/gpu/drm/vc4/vc4_hdmi.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 971c65a4d823..9ab83fc1cfab 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1378,7 +1378,9 @@ static int vc4_hdmi_audio_trigger(struct snd_pcm_substream *substream, int cmd,
HDMI_WRITE(HDMI_MAI_CTL,
VC4_SET_FIELD(vc4_hdmi->audio.channels,
VC4_HD_MAI_CTL_CHNUM) |
- VC4_HD_MAI_CTL_ENABLE);
+ VC4_HD_MAI_CTL_WHOLSMP |
+ VC4_HD_MAI_CTL_CHALIGN |
+ VC4_HD_MAI_CTL_ENABLE);
break;
case SNDRV_PCM_TRIGGER_STOP:
HDMI_WRITE(HDMI_MAI_CTL,