drm/vc4: hdmi: Set HD_CTL_WHOLSMP and HD_CTL_CHALIGN_SET
authorDom Cobley <popcornmix@gmail.com>
Tue, 25 May 2021 13:23:48 +0000 (15:23 +0200)
committerMaxime Ripard <maxime@cerno.tech>
Wed, 23 Jun 2021 12:32:27 +0000 (14:32 +0200)
commit1698ecb218eb82587dbfc71a2e26ded66e5ecf59
tree48771977eb946bff77922881c888d654a8ad02f8
parentecd3ee3d0c734b9454fc59cbe268c6be26f369e8
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
drivers/gpu/drm/vc4/vc4_hdmi.c