drm/qxl: cover all crtcs in shadow bo.

Browse source

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

...

This commit is contained in:

Gerd Hoffmann 2019-01-18 13:20:11 +01:00

parent 4979904c62

commit 90adda2ce8

3 changed files with 108 additions and 29 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

123

drivers/gpu/drm/qxl/qxl_display.c

View file

9

drivers/gpu/drm/qxl/qxl_draw.c

View file

5

drivers/gpu/drm/qxl/qxl_drv.h

View file