tests/kms_chamelium: add dp-audio test

This new test ensures DisplayPort audio works by using the Chamelium.

It enables the DisplayPort output and sends an audio signal containing a set of
frequencies we choose to all HDMI/DisplayPort audio devices. It starts
recording audio on the Chamelium device and uses the stream server to retrieve
captured audio pages. It then checks that the capture audio signal contains the
frequencies we sent, and only those, by computing a FFT.

A new library has been added to libigt to communicate with the stream server.
It implements a simple custom TCP protocol.

In case the test fails, a WAV file with the captured data is saved on disk.

Right now the test has a few limitations:

- Only the first channel is checked
- IGT only generates audio with a single sampling rate (48 KHz)
- Audio data is not captured in real-time

These limitations will be lifted in future patches.

PulseAudio must not run during the tests since ALSA is used directly. To ensure
this, edit /etc/pulse/client.conf and add `autospawn=no`. Then run
`pulseaudio --kill`.

This commit deletes the existing audio tests. They weren't run and required an
exotic configuration (HDMI audio splitter, dummy HDMI sink and a line-in port
on the DUT).

This patch also changes lib/igt_audio to use uint16_t instead of short. The
rationale is:

- The standard says a short is at least 16 bit wide, but a short can be
  larger (in practice it won't happen, but better use types correctly)
- It makes it clearer that the audio format is S16_LE, since "16" is
  in the type name.

This patch depends on the following Chameleon bugs:

- https://crbug.com/948060
- https://crbug.com/950857

Signed-off-by: Simon Ser <simon.ser@intel.com>
Reviewed-by: Martin Peres <martin.peres@linux.intel.com>

1 files changed, 19 insertions, 33 deletions

diff --git a/meson.build b/meson.build
index 557400a5..be6dff9d 100644
--- a/meson.build
+++ b/meson.build
@@ -64,8 +64,6 @@ _build_overlay = false
 _overlay_required = false
 _build_man = false
 _man_required = false
-_build_audio = false
-_audio_required = false
 _build_chamelium = false
 _chamelium_required = false
 _build_docs = false
@@ -79,7 +77,6 @@ build_overlay = get_option('build_overlay')
 overlay_backends = get_option('overlay_backends')
 build_man = get_option('build_man')
 with_valgrind = get_option('with_valgrind')
-build_audio = get_option('build_audio')
 build_chamelium = get_option('build_chamelium')
 build_docs = get_option('build_docs')
 build_tests = get_option('build_tests')
@@ -91,8 +88,6 @@ _build_overlay = build_overlay != 'false'
 _overlay_required = build_overlay == 'true'
 _build_man = build_man != 'false'
 _man_required = build_man == 'true'
-_build_audio = build_audio != 'false'
-_audio_required = build_audio == 'true'
 _build_chamelium = build_chamelium != 'false'
 _chamelium_required = build_chamelium == 'true'
 _build_docs = build_docs != 'false'
@@ -166,26 +161,6 @@ cairo = dependency('cairo', version : '>1.12.0', required : true)
 libudev = dependency('libudev', required : true)
 glib = dependency('glib-2.0', required : true)
 
-gsl = null_dep
-alsa = null_dep
-if _build_audio or _build_chamelium
-	gsl = dependency('gsl', required : _audio_required or _chamelium_required)
-endif
-if _build_audio
-	alsa = dependency('alsa', required : _audio_required)
-endif
-
-audioinfo = 'No'
-if _build_audio and alsa.found() and gsl.found()
-	audioinfo = 'Yes'
-else
-	if _audio_required
-		error('Cannot build audio test due to missing dependencies')
-	endif
-	_build_audio = false
-endif
-build_info += 'Build audio test: ' + audioinfo
-
 xmlrpc = dependency('xmlrpc', required : false)
 xmlrpc_util = dependency('xmlrpc_util', required : false)
 xmlrpc_client = dependency('xmlrpc_client', required : false)
@@ -197,21 +172,32 @@ if not xmlrpc.found() and xmlrpc_cmd.found()
 
 	if libs_cmd.returncode() == 0 and cflags_cmd.returncode() == 0
 		xmlrpc = declare_dependency(compile_args: cflags_cmd.stdout().strip().split(),
-					   link_args : libs_cmd.stdout().strip().split())
+					    link_args : libs_cmd.stdout().strip().split())
 		xmlrpc_util = declare_dependency()
 		xmlrpc_client = declare_dependency()
 	endif
 endif
 
+gsl = null_dep
+alsa = null_dep
 chamelium = null_dep
+chamelium_found = false # TODO: use a disabler object instead
 chameliuminfo = 'No'
-if _build_chamelium and gsl.found() and xmlrpc.found() and xmlrpc_util.found() and xmlrpc_client.found()
-	chamelium = declare_dependency(dependencies : [ xmlrpc,
-							xmlrpc_util, xmlrpc_client])
-	config.set('HAVE_CHAMELIUM', 1)
-	chameliuminfo = 'Yes'
-elif _chamelium_required
-	error('Cannot build chamelium test due to missing dependencies')
+if _build_chamelium
+	gsl = dependency('gsl', required : _chamelium_required)
+	alsa = dependency('alsa', required : _chamelium_required)
+	chamelium = declare_dependency(dependencies : [
+		xmlrpc,
+		xmlrpc_util,
+		xmlrpc_client,
+		gsl,
+		alsa,
+	], required : _chamelium_required)
+	if xmlrpc.found() and xmlrpc_util.found() and xmlrpc_client.found() and gsl.found() and alsa.found()
+		config.set('HAVE_CHAMELIUM', 1)
+		chameliuminfo = 'Yes'
+		chamelium_found = true
+	endif
 endif
 build_info += 'Build Chamelium test: ' + chameliuminfo