meta-pipewire: improve audio on iMX8MQ

As a an initial step to solve audio issues on iMX8MQ add a patch to
reduce the period_size and in that sense have better control about
buffers usage.

Bug-AGL: SPEC-3410

Signed-off-by: Walter Lozano <walter.lozano@collabora.com>
Change-Id: I0125515fc7ef6f0c9dbd6336d56d348d41f9115f
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/25093
Tested-by: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-build: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-boot-test: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>

diff --git a/meta-pipewire/recipes-multimedia/pipewire/pipewire/0007-alsa-Set-period_size-depending-on-hardware.patch b/meta-pipewire/recipes-multimedia/pipewire/pipewire/0007-alsa-Set-period_size-depending-on-hardware.patch
new file mode 100644 (file)
index 0000000..f964940
--- /dev/null
+++ b/meta-pipewire/recipes-multimedia/pipewire/pipewire/0007-alsa-Set-period_size-depending-on-hardware.patch
@@ -0,0 +1,35 @@
+From bbf9c767d5b353142e03080762bdd805e124d50b Mon Sep 17 00:00:00 2001
+From: Walter Lozano <walter.lozano@collabora.com>
+Date: Fri, 7 Aug 2020 10:58:29 -0300
+Subject: [PATCH] alsa: Set period_size depending on hardware
+
+Currently PipeWire is unable to reproduce audio in systems where DMA
+granularity is not burst.
+
+In order to mitigate this issue, set period_size depending on hardware,
+lowering it when snd_pcm_hw_params_is_batch == 1, to reduce DMA
+transfers size.
+
+Signed-off-by: Walter Lozano <walter.lozano@collabora.com>
+---
+ spa/plugins/alsa/alsa-pcm.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/spa/plugins/alsa/alsa-pcm.c b/spa/plugins/alsa/alsa-pcm.c
+index 63d75549..2d3850b7 100644
+--- a/spa/plugins/alsa/alsa-pcm.c
++++ b/spa/plugins/alsa/alsa-pcm.c
+@@ -463,6 +463,10 @@ int spa_alsa_set_format(struct state *state, struct spa_audio_info *fmt, uint32_
+ 
+       dir = 0;
+       period_size = 1024;
++      if (snd_pcm_hw_params_is_batch(params)) {
++              period_size = 512;
++              spa_log_warn(state->log, NAME" hardware does double buffering, changing period_size to %ld", period_size);
++      }
+       CHECK(snd_pcm_hw_params_set_period_size_near(hndl, params, &period_size, &dir), "set_period_size_near");
+       CHECK(snd_pcm_hw_params_get_buffer_size_max(params, &state->buffer_frames), "get_buffer_size_max");
+       CHECK(snd_pcm_hw_params_set_buffer_size_near(hndl, params, &state->buffer_frames), "set_buffer_size_near");
+-- 
+2.20.1
+

diff --git a/meta-pipewire/recipes-multimedia/pipewire/pipewire_git.bb b/meta-pipewire/recipes-multimedia/pipewire/pipewire_git.bb
index 1a4e4eb..7ca4237 100644 (file)
--- a/meta-pipewire/recipes-multimedia/pipewire/pipewire_git.bb
+++ b/meta-pipewire/recipes-multimedia/pipewire/pipewire_git.bb
@@ -7,6 +7,7 @@ SRC_URI = "git://gitlab.freedesktop.org/pipewire/pipewire.git;protocol=https;bra
     file://0004-audioconvert-always-assume-that-output-ports-are-NOT.patch \
     file://0005-module-access-add-same-sec-label-mode.patch \
     file://0006-alsa-pcm-call-reuse_buffers-when-resetting-the-state.patch \
+    file://0007-alsa-Set-period_size-depending-on-hardware.patch \
     "
 
 SRCREV = "b0932e687fc47e0872ca291531f2291d99042d70"