Since we cache already all the KMS parameters we care about let's check at
each device update if anything has really changed and only in such case
emit a resources-changed signal.
In this way we can also filter out the DRM parameters that when changed
don't require a full monitors rebuild.
Examples are the gamma settings or the privacy screen parameters, that
emits an udev "hotplug" event when changed, but we want to register those
only when we handle the changed property.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1964>
With atomic mode setting, commits don't work when CRTCs aren't enabled,
which they aren't when we're power saving. This means the gamma state
fails to being update. To fix night light and for whatever other reason
gamma ramps was changed during power saving by marking the CRTC gamma
state as invalid when leaving power saving, as well as when resuming.
This means that the next frame will append the CRTC gamma state to the
KMS commit.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1755
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1835>
Virtual monitors are monitors that isn't backed by any monitor like
hardware. It would typically be backed by e.g. a remote desktop service,
or a network display.
It is currently only supported by the native backend, and whether the
X11 backend will ever see virtual monitors is an open question. This
rest of this commit message describes how it works under the native
backend.
Each virutal monitor consists of virtualized mode setting components:
* A virtual CRTC mode (MetaCrtcModeVirtual)
* A virtual CRTC (MetaCrtcVirtual)
* A virtual connector (MetaOutputVirtual)
In difference to the corresponding mode setting objects that represents
KMS objects, the virtual ones isn't directly tied to a MetaGpu, other
than the CoglFramebuffer being part of the GPU context of the primary
GPU, which is the case for all monitors no matter what GPU they are
connected to. Part of the reason for this is that a MetaGpu in practice
represents a mode setting device, and its CRTCs and outputs, are all
backed by real mode setting objects, while a virtual monitor is only
backed by a framebuffer that is tied to the primary GPU. Maybe this will
be reevaluated in the future, but since a virtual monitor is not tied to
any GPU currently, so is the case for the virtual mode setting objects.
The native rendering backend, including the cursor renderer, is adapted
to handle the situation where a CRTC does not have a GPU associated with
it; this in practice means that it e.g. will not try to upload HW cursor
buffers when the cursor is only on a virtual monitor. The same applies
to the native renderer, which is made to avoid creating
MetaOnscreenNative for views that are backed by virtual CRTCs, as well
as to avoid trying to mode set on such views.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
