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Add support for CPU DMA latency requests

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This commit is contained in:
Robin Gareus
2021-06-10 04:26:44 +02:00
parent 2e574a011a
commit 8c0ef7bd62
2 changed files with 43 additions and 0 deletions
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1
libs/ardour/ardour/rc_configuration_vars.h
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@@ -218,6 +218,7 @@ CONFIG_VARIABLE_SPECIAL (std::string, default_session_parent_dir, "default-sessi
#endif
CONFIG_VARIABLE (bool, allow_special_bus_removal, "allow-special-bus-removal", false)
CONFIG_VARIABLE (int32_t, processor_usage, "processor-usage", -1)
CONFIG_VARIABLE (int32_t, cpu_dma_latency, "cpu-dma-latency", 0) /* >=0 to enable */
CONFIG_VARIABLE (gain_t, max_gain, "max-gain", 2.0) /* +6.0dB */
CONFIG_VARIABLE (uint32_t, max_recent_sessions, "max-recent-sessions", 10)
CONFIG_VARIABLE (uint32_t, max_recent_templates, "max-recent-templates", 10)

42
libs/ardour/globals.cc
View File

@@ -166,6 +166,7 @@ std::map<std::string, bool> ARDOUR::reserved_io_names;
static bool have_old_configuration_files = false;
static bool running_from_gui = false;
static int cpu_dma_latency_fd = -1;
namespace ARDOUR {
extern void setup_enum_writer ();
@@ -283,6 +284,42 @@ setup_hardware_optimization (bool try_optimization)
AudioGrapher::Routines::override_apply_gain_to_buffer (apply_gain_to_buffer);
}
static bool
request_dma_latency ()
{
#if !(defined PLATFORM_WINDOWS || defined __APPLE__)
if (!Glib::file_test ("/dev/cpu_dma_latency", Glib::FILE_TEST_EXISTS)) {
return false;
}
/* maximum latency in usecs, or 0 to prevent transitions to deep sleep states */
int32_t target = Config->get_cpu_dma_latency ();
cpu_dma_latency_fd = ::open("/dev/cpu_dma_latency", O_WRONLY);
if (cpu_dma_latency_fd < 0) {
warning << string_compose (_("Could not set DMA latency to %1 usec (%2)"), target, strerror (errno)) << endmsg;
return false;
}
if (::write (cpu_dma_latency_fd, &target, sizeof(target)) > 0) {
info << string_compose (_("Set DMA latency to %1 usec"), target) << endmsg;
} else {
warning << string_compose (_("Could not set DMA latency to %1 usec (%2)"), target, strerror (errno)) << endmsg;
}
#endif
return true;
}
static void
release_dma_latency ()
{
#if !(defined PLATFORM_WINDOWS || defined __APPLE__)
if (cpu_dma_latency_fd >= 0) {
::close (cpu_dma_latency_fd);
}
cpu_dma_latency_fd = -1;
#endif
}
static void
lotsa_files_please ()
{
@@ -564,6 +601,10 @@ ARDOUR::init (bool use_windows_vst, bool try_optimization, const char* localedir
setup_hardware_optimization (try_optimization);
if (Config->get_cpu_dma_latency () >= 0) {
request_dma_latency ();
}
SourceFactory::init ();
Analyser::init ();
@@ -669,6 +710,7 @@ ARDOUR::cleanup ()
return;
}
release_dma_latency ();
engine_startup_connection.disconnect ();
delete &ControlProtocolManager::instance ();