This change replaces abort() with Q_ASSERT and Q_UNREACHABLE() macros to
make kwin code base consistent. Besides that, Q_UNREACHABLE may
potentially provide the compiler more info that can be used to generate
more efficient machine code.
Instead of only allowing the current format, send the default tranches modified
to only contain formats and modifiers suitable for scanout.
In order to not fail when we can't do direct scanout with a given format
(because that may require a modeset, which we don't allow), keep a blacklist
of attempted formats and modifiers for the current client.
The fixed size of 1080p makes windows change their size and place. To
prevent that from happening, make the placeholder screen the same size
as the last disconnected screen.
This is not a bullet proof solution, only a fast one. Ideally KWin
should remember the window layout on a given monitor setup and restore
it when reconnected.
BUG: 447419
FIXED-IN: 5.24
On X11, if buffer age is unsupported, kwin can do some quirks like
copying parts of the front buffer to back buffer to avoid repainting the
whole screen.
Currently, the copying is performed in the opengl scene, which is not
perfect because it makes the scene responsible not only for painting the
scene but also some low level platform specific shenanigans.
This change moves the copying step to the glx and egl backends. It
simplifies the opengl scene, makes it less overloaded and more open to
changes, but it also duplicates code, which is not ideal. However, given
the de-facto deprecated state of the X11 platform, it's sort of acceptable
as the main focus is now on wayland session and the things that are
needed to make it fly as expected.
This commit makes 10 bits per color channel the default color depth, which
should reduce banding on outputs that support color formats with more than
8 bits per color channel. In order to support this the commit also removes
the dependency of the EglGbmBackend on a specific format and EglConfig and
instead makes those per-Output properties.
Currently, if you move the cursor really fast between two outputs, there
may be stuck cursor on the previous output.
We need to query the old cursor visibility status before updating the
cursor position, otherwise the drm backend may not schedule an update to
move the cursor offscreen.
This commit does away with the special handling of the legacy cursor and
makes it be applied directly in DrmPipeline, using the same state as the
atomic cursor and without dirty flags.
The cursor being set out-of-band with atomic commits creates problems
because it can create false positive for atomic tests, if the cursor
state gets changed in between an atomic test and its matching commit.
This commit also ports the cursor to a swapchain instead of only one
image. This is not strictly required but may prevent artifacts and
will be needed for future optimisations.
If eglSwapBuffers() fails, there won't be a buffer and so we need to
mark the frame as failed. Otherwise, the screen can be frozen.
eglSwapBuffers() can fail if some effect calls makeOpenGLContext()
between RenderBackend::beginFrame() and RenderBackend::endFrame(), which
is the case with the zoom effect. It can set wrong draw surface in
ZoomEffect::recreateTexture()
BUG: 445412
dmabuf-feedback allows the compositor to give the clients better feedback on what
formats and modifiers they should use, and for which device they should allocate.
This way they can reallocate for scanout whenever the compositor tells them to,
which makes direct scanout work for a lot more devices and applications.
While it could be useful with tiled displays, the isFormatSupported and
supportedModifier functions can be called before prepareModeset, so where
m_formats is still empty. Additionally they're neither in a hot path nor
performance critical.
Whether or not we want to use explicit modifiers for our surfaces doesn't
matter for what format+modifiers drm planes support. This way direct scanout
works by default, without having to explicitly enable modifiers
systemd takes care of setting and dropping master permissions when
sending PauseDevice and ResumeDevice signals.
When the ResumeDevice signal is received, the relevant drm device should
already have master permissions set up.
On the other hand, when the active property changes, there's still a
chance that systemd haven't granted drm master permissions to us.
In case a modeset needs to be performed, the drm backend will test all
pipelines to ensure that new mode won't cause any bandwidth issues on
other outputs, etc.
To do that, it may delay presenting frames. If the new configuration
doesn't work, it needs to notify about failed frames.
However, the relevant code that notifies the RenderLoop about failed
atomic commits doesn't check if there's actually a pending modeset
present.
When switching between VTs, systemd can revoke master permissions from
kwin. To make things even more trickier, kwin can try to present a frame
in that short time span.
