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platforms/drm: delay presentation for modesets

Browse source 
Currently KWin is combining modesets with presentation, which causes problems
when multiple monitors are used and crtcs need to be switched around, because
taking away a CRTC from another output causes the driver to disable the
other output. In order to avoid such problems, delay presentation until
all pipelines are ready to present and then do a modeset with a single atomic
commit. To process the resulting page flip events properly this commit also
ports KWin to page_flip_handler2 and changes how the pageFlipped and
notifyFrameFailed signals are processed.
This commit is contained in:
Xaver Hugl 2021-10-08 10:52:01 +02:00
parent e2a0863843
commit a07aae8282
14 changed files with 209 additions and 52 deletions
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3
src/backends/drm/drm_backend.cpp
View file

@ -763,6 +763,9 @@ bool DrmBackend::applyOutputChanges(const WaylandOutputConfig &config)
}
};
updateCursor();
if (auto compositor = Compositor::self()) {
compositor->addRepaintFull();
}
return true;
}

5
src/backends/drm/drm_buffer_gbm.cpp
View file

@ -83,6 +83,11 @@ bool GbmBuffer::map(uint32_t flags)
return m_data;
}
KWaylandServer::ClientBuffer *GbmBuffer::clientBuffer() const
{
return m_clientBuffer;
}
DrmGbmBuffer::DrmGbmBuffer(DrmGpu *gpu, GbmSurface *surface, gbm_bo *bo)
: DrmBuffer(gpu, gbm_bo_get_format(bo), gbm_bo_get_modifier(bo)), GbmBuffer(surface, bo)

1
src/backends/drm/drm_buffer_gbm.h
View file

@ -47,6 +47,7 @@ public:
uint32_t stride() const {
return m_stride;
}
KWaylandServer::ClientBuffer *clientBuffer() const;
protected:
GbmSurface *m_surface = nullptr;

88
src/backends/drm/drm_gpu.cpp
View file

@ -347,7 +347,30 @@ bool DrmGpu::checkCrtcAssignment(QVector<DrmConnector*> connectors, QVector<DrmC
qCWarning(KWIN_DRM) << "disabling connector" << conn->modelName() << "without a crtc";
conn->pipeline()->pending.crtc = nullptr;
}
return DrmPipeline::commitPipelines(m_pipelines, DrmPipeline::CommitMode::Test);
// non-desktop outputs need to be tested when they would be enabled so that they can be used if leased
QVector<DrmPipeline*> leasePipelines;
for (const auto &output : qAsConst(m_leaseOutputs)) {
if (!output->lease()) {
output->pipeline()->pending.active = true;
leasePipelines << output->pipeline();
}
}
bool test = DrmPipeline::commitPipelines(m_pipelines, DrmPipeline::CommitMode::Test);
if (!leasePipelines.isEmpty() && test) {
// non-desktop outputs should be disabled for normal usage
for (const auto &pipeline : qAsConst(leasePipelines)) {
pipeline->pending.active = false;
}
bool ret = DrmPipeline::commitPipelines(m_pipelines, DrmPipeline::CommitMode::Test);
if (ret) {
for (const auto &pipeline : qAsConst(leasePipelines)) {
pipeline->applyPendingChanges();
}
}
return ret;
} else {
return test;
}
}
auto connector = connectors.takeFirst();
auto pipeline = connector->pipeline();
@ -424,7 +447,7 @@ void DrmGpu::waitIdle()
m_socketNotifier->setEnabled(false);
while (true) {
const bool idle = std::all_of(m_drmOutputs.constBegin(), m_drmOutputs.constEnd(), [](DrmOutput *output){
return !output->m_pageFlipPending;
return !output->pipeline()->pageflipPending();
});
if (idle) {
break;
@ -471,10 +494,10 @@ static std::chrono::nanoseconds convertTimestamp(clockid_t sourceClock, clockid_
return convertTimestamp(targetCurrentTime) - delta;
}
static void pageFlipHandler(int fd, unsigned int frame, unsigned int sec, unsigned int usec, void *data)
void DrmGpu::pageFlipHandler(int fd, unsigned int sequence, unsigned int sec, unsigned int usec, unsigned int crtc_id, void *user_data)
{
Q_UNUSED(fd)
Q_UNUSED(frame)
Q_UNUSED(sequence)
Q_UNUSED(user_data)
auto backend = dynamic_cast<DrmBackend*>(kwinApp()->platform());
if (!backend) {
return;
@ -483,29 +506,28 @@ static void pageFlipHandler(int fd, unsigned int frame, unsigned int sec, unsign
if (!gpu) {
return;
}
auto output = static_cast<DrmOutput *>(data);
if (!gpu->outputs().contains(output)) {
// output already got deleted
return;
}
// The static_cast<> here are for a 32-bit environment where
// sizeof(time_t) == sizeof(unsigned int) == 4 . Putting @p sec
// into a time_t cuts off the most-significant bit (after the
// year 2038), similarly long can't hold all the bits of an
// unsigned multiplication.
std::chrono::nanoseconds timestamp = convertTimestamp(output->gpu()->presentationClock(),
CLOCK_MONOTONIC,
std::chrono::nanoseconds timestamp = convertTimestamp(gpu->presentationClock(), CLOCK_MONOTONIC,
{ static_cast<time_t>(sec), static_cast<long>(usec * 1000) });
if (timestamp == std::chrono::nanoseconds::zero()) {
qCDebug(KWIN_DRM, "Got invalid timestamp (sec: %u, usec: %u) on output %s",
sec, usec, qPrintable(output->name()));
qCDebug(KWIN_DRM, "Got invalid timestamp (sec: %u, usec: %u) on gpu %s",
sec, usec, qPrintable(gpu->devNode()));
timestamp = std::chrono::steady_clock::now().time_since_epoch();
}
output->pageFlipped();
RenderLoopPrivate *renderLoopPrivate = RenderLoopPrivate::get(output->renderLoop());
renderLoopPrivate->notifyFrameCompleted(timestamp);
const auto pipelines = gpu->pipelines();
auto it = std::find_if(pipelines.begin(), pipelines.end(), [crtc_id](const auto &pipeline) {
return pipeline->currentCrtc() && pipeline->currentCrtc()->id() == crtc_id;
});
if (it == pipelines.end()) {
qCWarning(KWIN_DRM, "received invalid page flip event for crtc %u", crtc_id);
} else {
(*it)->pageFlipped(timestamp);
}
}
void DrmGpu::dispatchEvents()
@ -514,8 +536,8 @@ void DrmGpu::dispatchEvents()
return;
}
drmEventContext context = {};
context.version = 2;
context.page_flip_handler = pageFlipHandler;
context.version = 3;
context.page_flip_handler2 = pageFlipHandler;
drmHandleEvent(m_fd, &context);
}
@ -707,4 +729,30 @@ bool DrmGpu::isNVidia() const
return m_isNVidia;
}
bool DrmGpu::needsModeset() const
{
return std::any_of(m_pipelines.constBegin(), m_pipelines.constEnd(), [](const auto &pipeline) {
return pipeline->needsModeset();
});
}
bool DrmGpu::maybeModeset()
{
auto pipelines = m_pipelines;
for (const auto &output : qAsConst(m_leaseOutputs)) {
if (output->lease()) {
pipelines.removeOne(output->pipeline());
}
}
bool presentPendingForAll = std::all_of(pipelines.constBegin(), pipelines.constEnd(), [](const auto &pipeline) {
return pipeline->modesetPresentPending() || !pipeline->pending.active;
});
if (presentPendingForAll) {
return DrmPipeline::commitPipelines(pipelines, DrmPipeline::CommitMode::CommitModeset);
} else {
// commit only once all pipelines are ready for presentation
return true;
}
}
}

5
src/backends/drm/drm_gpu.h
View file

@ -83,6 +83,9 @@ public:
DrmVirtualOutput *createVirtualOutput(const QString &name, const QSize &size, double scale, VirtualOutputMode mode);
void removeVirtualOutput(DrmVirtualOutput *output);
bool needsModeset() const;
bool maybeModeset();
Q_SIGNALS:
void outputAdded(DrmAbstractOutput *output);
void outputRemoved(DrmAbstractOutput *output);
@ -102,6 +105,8 @@ private:
void handleLeaseRequest(KWaylandServer::DrmLeaseV1Interface *leaseRequest);
void handleLeaseRevoked(KWaylandServer::DrmLeaseV1Interface *lease);
static void pageFlipHandler(int fd, unsigned int sequence, unsigned int sec, unsigned int usec, unsigned int crtc_id, void *user_data);
const int m_fd;
const dev_t m_deviceId;
const QString m_devNode;

3
src/backends/drm/drm_object_connector.cpp
View file

@ -306,6 +306,9 @@ bool DrmConnector::vrrCapable() const
bool DrmConnector::needsModeset() const
{
if (!gpu()->atomicModeSetting()) {
return false;
}
if (getProp(PropertyIndex::CrtcId)->needsCommit()) {
return true;
}

3
src/backends/drm/drm_object_crtc.cpp
View file

@ -54,6 +54,9 @@ drmModeModeInfo DrmCrtc::queryCurrentMode()
bool DrmCrtc::needsModeset() const
{
if (!gpu()->atomicModeSetting()) {
return false;
}
return getProp(PropertyIndex::Active)->needsCommit()
|| getProp(PropertyIndex::ModeId)->needsCommit();
}

3
src/backends/drm/drm_object_plane.cpp
View file

@ -168,6 +168,9 @@ void DrmPlane::setBuffer(DrmBuffer *buffer)
bool DrmPlane::needsModeset() const
{
if (!gpu()->atomicModeSetting()) {
return false;
}
auto rotation = getProp(PropertyIndex::Rotation);
if (rotation && rotation->needsCommit()) {
return true;

23
src/backends/drm/drm_output.cpp
View file

@ -69,9 +69,6 @@ DrmOutput::DrmOutput(DrmPipeline *pipeline)
DrmOutput::~DrmOutput()
{
if (m_pageFlipPending) {
pageFlipped();
}
m_pipeline->setOutput(nullptr);
}
@ -264,7 +261,7 @@ bool DrmOutput::setDrmDpmsMode(DpmsMode mode)
return true;
}
m_pipeline->pending.active = active;
if (DrmPipeline::commitPipelines({m_pipeline}, active ? DrmPipeline::CommitMode::Test : DrmPipeline::CommitMode::Commit)) {
if (DrmPipeline::commitPipelines({m_pipeline}, active ? DrmPipeline::CommitMode::Test : DrmPipeline::CommitMode::CommitModeset)) {
m_pipeline->applyPendingChanges();
setDpmsModeInternal(mode);
if (active) {
@ -370,13 +367,6 @@ bool DrmOutput::needsSoftwareTransformation() const
return m_pipeline->pending.transformation != outputToPlaneTransform(transform());
}
void DrmOutput::pageFlipped()
{
Q_ASSERT(m_pageFlipPending || !m_gpu->atomicModeSetting());
m_pageFlipPending = false;
m_pipeline->pageFlipped();
}
bool DrmOutput::present(const QSharedPointer<DrmBuffer> &buffer, QRegion damagedRegion)
{
if (!buffer || buffer->bufferId() == 0) {
@ -393,7 +383,6 @@ bool DrmOutput::present(const QSharedPointer<DrmBuffer> &buffer, QRegion damaged
}
}
if (m_pipeline->present(buffer)) {
m_pageFlipPending = true;
Q_EMIT outputChange(damagedRegion);
return true;
} else {
@ -494,4 +483,14 @@ void DrmOutput::revertQueuedChanges()
m_pipeline->revertPendingChanges();
}
void DrmOutput::pageFlipped(std::chrono::nanoseconds timestamp)
{
RenderLoopPrivate::get(m_renderLoop)->notifyFrameCompleted(timestamp);
}
void DrmOutput::presentFailed()
{
RenderLoopPrivate::get(m_renderLoop)->notifyFrameFailed();
}
}

6
src/backends/drm/drm_output.h
View file

@ -20,6 +20,7 @@
#include <QVector>
#include <QSharedPointer>
#include <xf86drmMode.h>
#include <chrono>
namespace KWin
{
@ -47,7 +48,6 @@ public:
bool moveCursor() override;
bool present(const QSharedPointer<DrmBuffer> &buffer, QRegion damagedRegion) override;
void pageFlipped();
DrmConnector *connector() const;
DrmPipeline *pipeline() const;
@ -61,6 +61,9 @@ public:
void applyQueuedChanges(const WaylandOutputConfig &config);
void revertQueuedChanges();
void pageFlipped(std::chrono::nanoseconds timestamp);
void presentFailed();
private:
friend class DrmGpu;
friend class DrmBackend;
@ -84,7 +87,6 @@ private:
DrmConnector *m_connector;
QSharedPointer<DrmDumbBuffer> m_cursor;
bool m_pageFlipPending = false;
QTimer m_turnOffTimer;
};

98
src/backends/drm/drm_pipeline.cpp
View file

@ -46,11 +46,21 @@ DrmPipeline::DrmPipeline(DrmConnector *conn)
DrmPipeline::~DrmPipeline()
{
m_output = nullptr;
if (m_pageflipPending && m_current.crtc) {
pageFlipped({});
}
}
bool DrmPipeline::present(const QSharedPointer<DrmBuffer> &buffer)
{
Q_ASSERT(pending.crtc);
if (!buffer) {
if (m_output) {
m_output->presentFailed();
}
return false;
}
m_primaryBuffer = buffer;
if (gpu()->useEglStreams() && gpu()->eglBackend() != nullptr && gpu() == gpu()->platform()->primaryGpu()) {
// EglStreamBackend queues normal page flips through EGL,
@ -59,19 +69,42 @@ bool DrmPipeline::present(const QSharedPointer<DrmBuffer> &buffer)
return true;
}
}
bool directScanout = false;
#if HAVE_GBM
// with direct scanout disallow modesets, calling presentFailed() and logging warnings
if (auto buf = dynamic_cast<DrmGbmBuffer*>(buffer.data()); buf && buf->clientBuffer()) {
directScanout = true;
}
#endif
if (gpu()->needsModeset()) {
if (directScanout) {
return false;
}
m_modesetPresentPending = true;
return gpu()->maybeModeset();
}
if (gpu()->atomicModeSetting()) {
if (!commitPipelines({this}, CommitMode::Commit)) {
// update properties and try again
updateProperties();
if (!commitPipelines({this}, CommitMode::Commit)) {
if (directScanout) {
return false;
}
qCWarning(KWIN_DRM) << "Atomic present failed!" << strerror(errno);
printDebugInfo();
if (m_output) {
m_output->presentFailed();
}
return false;
}
}
} else {
if (!presentLegacy()) {
qCWarning(KWIN_DRM) << "Present failed!" << strerror(errno);
if (m_output) {
m_output->presentFailed();
}
return false;
}
}
@ -87,8 +120,8 @@ bool DrmPipeline::commitPipelines(const QVector<DrmPipeline*> &pipelines, Commit
qCDebug(KWIN_DRM) << "Failed to allocate drmModeAtomicReq!" << strerror(errno);
return false;
}
uint32_t flags = DRM_MODE_ATOMIC_NONBLOCK;
const auto &failed = [pipelines, req](){
uint32_t flags = 0;
const auto &failed = [pipelines, req, mode](){
drmModeAtomicFree(req);
for (const auto &pipeline : pipelines) {
pipeline->printDebugInfo();
@ -101,6 +134,10 @@ bool DrmPipeline::commitPipelines(const QVector<DrmPipeline*> &pipelines, Commit
pipeline->pending.crtc->rollbackPending();
pipeline->pending.crtc->primaryPlane()->rollbackPending();
}
if (mode != CommitMode::Test && pipeline->activePending() && pipeline->output()) {
pipeline->m_modesetPresentPending = false;
pipeline->output()->presentFailed();
}
}
return false;
};
@ -114,11 +151,22 @@ bool DrmPipeline::commitPipelines(const QVector<DrmPipeline*> &pipelines, Commit
return failed();
}
}
if (drmModeAtomicCommit(pipelines[0]->gpu()->fd(), req, (flags & (~DRM_MODE_PAGE_FLIP_EVENT)) | DRM_MODE_ATOMIC_TEST_ONLY, pipelines[0]->output()) != 0) {
bool modeset = flags & DRM_MODE_ATOMIC_ALLOW_MODESET;
Q_ASSERT(!modeset || mode != CommitMode::Commit);
if (modeset) {
// The kernel fails commits with DRM_MODE_PAGE_FLIP_EVENT when a crtc is disabled in the commit
// and already was disabled before, to work around some quirks in old userspace.
// Instead of using DRM_MODE_PAGE_FLIP_EVENT | DRM_MODE_ATOMIC_NONBLOCK, do the modeset in a blocking
// fashion without page flip events and directly call the pageFlipped method afterwards
flags = flags & (~DRM_MODE_PAGE_FLIP_EVENT);
} else {
flags |= DRM_MODE_ATOMIC_NONBLOCK;
}
if (drmModeAtomicCommit(pipelines[0]->gpu()->fd(), req, (flags & (~DRM_MODE_PAGE_FLIP_EVENT)) | DRM_MODE_ATOMIC_TEST_ONLY, nullptr) != 0) {
qCWarning(KWIN_DRM) << "Atomic test for" << mode << "failed!" << strerror(errno);
return failed();
}
if (mode != CommitMode::Test && drmModeAtomicCommit(pipelines[0]->gpu()->fd(), req, flags, pipelines[0]->output()) != 0) {
if (mode != CommitMode::Test && drmModeAtomicCommit(pipelines[0]->gpu()->fd(), req, flags, nullptr) != 0) {
qCWarning(KWIN_DRM) << "Atomic commit failed! This should never happen!" << strerror(errno);
return failed();
}
@ -130,6 +178,8 @@ bool DrmPipeline::commitPipelines(const QVector<DrmPipeline*> &pipelines, Commit
pipeline->pending.crtc->primaryPlane()->commitPending();
}
if (mode != CommitMode::Test) {
pipeline->m_modesetPresentPending = false;
pipeline->m_pageflipPending = true;
pipeline->m_connector->commit();
if (pipeline->pending.crtc) {
pipeline->pending.crtc->primaryPlane()->setNext(pipeline->m_primaryBuffer);
@ -137,6 +187,9 @@ bool DrmPipeline::commitPipelines(const QVector<DrmPipeline*> &pipelines, Commit
pipeline->pending.crtc->primaryPlane()->commit();
}
pipeline->m_current = pipeline->pending;
if (modeset && pipeline->activePending()) {
pipeline->pageFlipped(std::chrono::steady_clock::now().time_since_epoch());
}
}
}
drmModeAtomicFree(req);
@ -152,11 +205,21 @@ bool DrmPipeline::commitPipelines(const QVector<DrmPipeline*> &pipelines, Commit
if (failure) {
// at least try to revert the config
for (const auto &pipeline : pipelines) {
pipeline->pending = pipeline->m_next;
pipeline->revertPendingChanges();
pipeline->applyPendingChangesLegacy();
if (mode == CommitMode::CommitModeset && pipeline->output() && pipeline->activePending()) {
pipeline->output()->presentFailed();
}
}
return false;
} else {
for (const auto &pipeline : pipelines) {
pipeline->applyPendingChanges();
pipeline->m_current = pipeline->pending;
if (mode == CommitMode::CommitModeset && mode != CommitMode::Test && pipeline->activePending()) {
pipeline->pageFlipped(std::chrono::steady_clock::now().time_since_epoch());
}
}
return true;
}
}
@ -201,6 +264,7 @@ bool DrmPipeline::presentLegacy()
qCWarning(KWIN_DRM) << "Page flip failed:" << strerror(errno) << m_primaryBuffer;
return false;
}
m_pageflipPending = true;
pending.crtc->setNext(m_primaryBuffer);
return true;
}
@ -378,12 +442,16 @@ DrmGpu *DrmPipeline::gpu() const
return m_connector->gpu();
}
void DrmPipeline::pageFlipped()
void DrmPipeline::pageFlipped(std::chrono::nanoseconds timestamp)
{
m_current.crtc->flipBuffer();
if (m_current.crtc->primaryPlane()) {
m_current.crtc->primaryPlane()->flipBuffer();
}
m_pageflipPending = false;
if (m_output) {
m_output->pageFlipped(timestamp);
}
}
void DrmPipeline::setOutput(DrmOutput *output)
@ -426,7 +494,8 @@ bool DrmPipeline::needsModeset() const
|| pending.active != m_current.active
|| pending.modeIndex != m_current.modeIndex
|| pending.rgbRange != m_current.rgbRange
|| pending.transformation != m_current.transformation;
|| pending.transformation != m_current.transformation
|| m_modesetPresentPending;
}
bool DrmPipeline::activePending() const
@ -439,6 +508,21 @@ void DrmPipeline::revertPendingChanges()
pending = m_next;
}
bool DrmPipeline::pageflipPending() const
{
return m_pageflipPending;
}
bool DrmPipeline::modesetPresentPending() const
{
return m_modesetPresentPending;
}
DrmCrtc *DrmPipeline::currentCrtc() const
{
return m_current.crtc;
}
DrmGammaRamp::DrmGammaRamp(DrmGpu *gpu, const GammaRamp &lut)
: lut(lut)
, size(lut.size())

12
src/backends/drm/drm_pipeline.h
View file

@ -15,6 +15,7 @@
#include <QSharedPointer>
#include <xf86drmMode.h>
#include <chrono>
#include "drm_object_plane.h"
#include "renderloop_p.h"
@ -54,6 +55,7 @@ public:
bool present(const QSharedPointer<DrmBuffer> &buffer);
bool needsModeset() const;
bool needsCommit() const;
void prepareModeset();
void applyPendingChanges();
void revertPendingChanges();
@ -65,9 +67,12 @@ public:
QPoint cursorPos() const;
DrmConnector *connector() const;
DrmCrtc *currentCrtc() const;
DrmGpu *gpu() const;
void pageFlipped();
void pageFlipped(std::chrono::nanoseconds timestamp);
bool pageflipPending() const;
bool modesetPresentPending() const;
void printDebugInfo() const;
QSize sourceSize() const;
void updateProperties();
@ -92,7 +97,8 @@ public:
enum class CommitMode {
Test,
Commit
Commit,
CommitModeset
};
Q_ENUM(CommitMode);
static bool commitPipelines(const QVector<DrmPipeline*> &pipelines, CommitMode mode);
@ -111,6 +117,8 @@ private:
QSharedPointer<DrmBuffer> m_primaryBuffer;
QSharedPointer<DrmBuffer> m_oldTestBuffer;
bool m_pageflipPending = false;
bool m_modesetPresentPending = false;
QMap<uint32_t, QVector<uint64_t>> m_formats;
int m_lastFlags = 0;

6
src/backends/drm/egl_gbm_backend.cpp
View file

@ -581,11 +581,7 @@ void EglGbmBackend::endFrame(AbstractOutput *drmOutput, const QRegion &renderedR
const QRegion dirty = damagedRegion.intersected(output.output->geometry());
QSharedPointer<DrmBuffer> buffer = endFrameWithBuffer(drmOutput, dirty);
if (!buffer || !output.output->present(buffer, dirty)) {
RenderLoopPrivate *renderLoopPrivate = RenderLoopPrivate::get(output.output->renderLoop());
renderLoopPrivate->notifyFrameFailed();
return;
}
output.output->present(buffer, dirty);
}
void EglGbmBackend::updateBufferAge(Output &output, const QRegion &dirty)

5
src/backends/drm/scene_qpainter_drm_backend.cpp
View file

@ -78,10 +78,7 @@ void DrmQPainterBackend::endFrame(AbstractOutput *output, const QRegion &damage)
QSharedPointer<DrmDumbBuffer> back = rendererOutput.swapchain->currentBuffer();
rendererOutput.swapchain->releaseBuffer(back);
if (!drmOutput->present(back, drmOutput->geometry())) {
RenderLoopPrivate *renderLoopPrivate = RenderLoopPrivate::get(drmOutput->renderLoop());
renderLoopPrivate->notifyFrameFailed();
}
drmOutput->present(back, drmOutput->geometry());
rendererOutput.damageJournal.add(damage);
}