kwin/src/backends/drm/scene_qpainter_drm_backend.cpp
Xaver Hugl a07aae8282 platforms/drm: delay presentation for modesets
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.
2021-11-09 22:15:31 +01:00

86 lines
2.4 KiB
C++

/*
KWin - the KDE window manager
This file is part of the KDE project.
SPDX-FileCopyrightText: 2015 Martin Gräßlin <mgraesslin@kde.org>
SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "scene_qpainter_drm_backend.h"
#include "drm_backend.h"
#include "drm_output.h"
#include "drm_gpu.h"
#include "renderloop_p.h"
namespace KWin
{
DrmQPainterBackend::DrmQPainterBackend(DrmBackend *backend, DrmGpu *gpu)
: QPainterBackend()
, m_backend(backend)
, m_gpu(gpu)
{
const auto outputs = m_backend->drmOutputs();
for (auto output: outputs) {
initOutput(output);
}
connect(m_gpu, &DrmGpu::outputEnabled, this, &DrmQPainterBackend::initOutput);
connect(m_gpu, &DrmGpu::outputDisabled, this,
[this] (DrmAbstractOutput *o) {
auto it = std::find_if(m_outputs.begin(), m_outputs.end(),
[o] (const Output &output) {
return output.output == o;
}
);
if (it == m_outputs.end()) {
return;
}
m_outputs.erase(it);
}
);
}
void DrmQPainterBackend::initOutput(DrmAbstractOutput *output)
{
Output o;
o.swapchain = QSharedPointer<DumbSwapchain>::create(m_gpu, output->pixelSize());
o.output = output;
m_outputs.insert(output, o);
connect(output, &DrmOutput::currentModeChanged, this,
[output, this] {
auto &o = m_outputs[output];
o.swapchain = QSharedPointer<DumbSwapchain>::create(m_gpu, output->pixelSize());
o.damageJournal.setCapacity(o.swapchain->slotCount());
}
);
}
QImage *DrmQPainterBackend::bufferForScreen(AbstractOutput *output)
{
return m_outputs[output].swapchain->currentBuffer()->image();
}
QRegion DrmQPainterBackend::beginFrame(AbstractOutput *output)
{
Output *rendererOutput = &m_outputs[output];
int bufferAge;
rendererOutput->swapchain->acquireBuffer(&bufferAge);
return rendererOutput->damageJournal.accumulate(bufferAge, rendererOutput->output->geometry());
}
void DrmQPainterBackend::endFrame(AbstractOutput *output, const QRegion &damage)
{
Output &rendererOutput = m_outputs[output];
DrmAbstractOutput *drmOutput = rendererOutput.output;
QSharedPointer<DrmDumbBuffer> back = rendererOutput.swapchain->currentBuffer();
rendererOutput.swapchain->releaseBuffer(back);
drmOutput->present(back, drmOutput->geometry());
rendererOutput.damageJournal.add(damage);
}
}