pain and redemption on the linux desktop linux graphics...

Pain and Redemption on the Linux DesktopKeith Packard

Linux Graphics Principal [email protected]

2008‒2‒1

Pain and Redemption on the Linux Desktop

What would make us happy

1 Pain and Redemption on the Linux Desktop


What would make us happyHow sad we are today



What would make us happyHow sad we are todayWhere the ice cream can be found


Features of a Happy Desktop

Fully composited (♥♥♥ compiz ♥♥♥)No tearingIntegrated video, 3D, 2D APIsFlicker-free bootFast user switchingHotplug everywhereLower powerFaster. Everywhere.Reducing root code


Where Are We NowThe long and winding road…

Composted Desktop

2D: Stylin'Textured video works greatOverlay video cannot work3D: not so much


Tear Free

3D onlyEndangers kittens


API Integration

Video cannot draw to pixmapsVideo sometimes uses overlays3D cannot draw to/from pixmaps2D cannot draw to/from texturesMajor loss here.


Flicker-free Booting

Hardware Logo screenGrubKernel messagesKernel console font settingFlash to blackFlash to backlight offFlash to solid colorFlash to GDM login


Fast User Switching

VT switch is so prettyLimited to one 3D session at a time


Hotplug Everywhere

Video output switching works finallyCannot resize framebufferOne framebuffer per GPU. GPU limits max width.


Lower power

Framebuffer Compression2D spins on GPU3D melts CPU, has inefficient compilerVideo uses small piece of GPU


Faster

Render needs to be acceleratedVideo needs MC accel at least3D GLSL compiler is primitive


X Security Issues

Entire X server runs as rootX server maps all I/O portsX server maps graphics cardNo longer directly configures PCI (yay!)


How Do We Get To Oz?Follow the yellow brick road…

Compositing 3D Applications

Eliminate shared back/depth buffersCreate per-window back/depth buffersSwap buffers to window redirection bufferDRI2 demo already done by KRH


Syncronizing to Retrace

2D application/compositing mgr conventionsXvPutImage needs to use DRM buffer swapAIGLX needs to use DRM buffer swapNothing going on here


Integrated drawing APIs

Video: XvPutImage to pixmap. Abondon overlays3D: GLX draw to X pixmaps. X reference GLX texturesTTM-based 2D driver on a branch


Flicker Free Boot

DRM-based mode settinggraphical console on top of DRMhandwaving for correct default modeDRM stuff is on a branch


Fast user switching

Multiple DRM mastersMultiple frame buffers in DRMCode is in Fedora, not upstream yet


Resize framebuffer

Move to EXAFinish TTM transitionFix 3D driver to actually checkEric says this requires us to abandon existing DRI apps


Shatter: multiple framebuffers

Spilt screen across framebuffersMultiple clip lists for each windowMultiple back/depth-buffers for each window for 3DAjax has some ideas and a bit of code


Lower power

DRM-based 2D driversXvMC support extended to non-MPEG formatsJbarnes hacking on more LVDS power savingZhenyu has XvMC for 915 and 965Airlied has DRM 2D drivers.


Faster

Pervasive Render accelerationEric and Carl have 965 going much better


Security

Kernel mode settingDRM-based 2D drawingX server runs as 'nobody'Jbarnes and Airlied have demos working


pain and redemption on the linux desktop linux graphics...

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