mainlining shenanigans
90adda2ce8
The qxl device supports only a single active framebuffer ("primary
surface" in spice terminology). In multihead configurations are handled
by defining rectangles within the primary surface for each head/crtc.
Userspace which uses the qxl ioctl interface (xorg qxl driver) is aware
of this limitation and will setup framebuffers and crtcs accordingly.
Userspace which uses dumb framebuffers (xorg modesetting driver,
wayland) is not aware of this limitation and tries to use two
framebuffers (one for each crtc) instead.
The qxl kms driver already has the dumb bo separated from the primary
surface, by using a (shared) shadow bo as primary surface. This is
needed to support pageflips without having to re-create the primary
surface. The qxl driver will blit from the dumb bo to the shadow bo
instead.
So we can extend the shadow logic: Maintain a global shadow bo (aka
primary surface), make it big enough that dumb bo's for all crtcs fit in
side-by-side. Adjust the pageflip blits to place the heads next to each
other in the shadow.
With this patch in place multihead qxl works with wayland.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20190118122020.27596-15-kraxel@redhat.com
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.