Our handling of the crtc timing computation has been nicely
cargo-culted with calls to drm_mode_set_crtcinfo sprinkled all over
the place. But with
commit f9bef081c3
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Sun Apr 15 19:53:19 2012 +0200
drm/i915: don't clobber the special upscaling lvds timings
and
commit ca9bfa7eed
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Sat Jan 28 14:49:20 2012 +0100
drm/i915: fixup interlaced vertical timings confusion, part 1
we now only set the crtc timing fields in the encoder->mode_fixup
(lvds only) and in crtc->mode_fixup (for everyone else). And since
commit 75c13993db
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Sat Jan 28 23:48:46 2012 +0100
drm/i915: fixup overlay checks for interlaced modes
the only places we actually need the crtc timings is in the mode_set
function.
I guess the idea of the drm core is that every time it creates a drm
mode, it also sets the timings. But afaics it never uses them, safe
for the precise vblank timestamp code (but that can only run on active
modes, i.e. after our mode_fixup functions have been called). The
problem is that drm core always sets CRTC_INTERLACE_HALVE_V, so the
timings are pretty much bogus for us anyway (at least with interlaced
support).
So I guess it's the drivers job that every active modes needs to have
crtc timings that suits it, and with these patches we should have
that. drm core doesn't seem to care about modes that just get passed
around. Hence we can now safely rip out all the remaining calls to
set_crtcinfo left in the driver and clean up this confusion.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
************************************************************
* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
************************************************************
The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).
The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:
1. The DRM provides synchronized access to the graphics hardware via
the use of an optimized two-tiered lock.
2. The DRM enforces the DRI security policy for access to the graphics
hardware by only allowing authenticated X11 clients access to
restricted regions of memory.
3. The DRM provides a generic DMA engine, complete with multiple
queues and the ability to detect the need for an OpenGL context
switch.
4. The DRM is extensible via the use of small device-specific modules
that rely extensively on the API exported by the DRM module.
Documentation on the DRI is available from:
http://dri.freedesktop.org/wiki/Documentation
http://sourceforge.net/project/showfiles.php?group_id=387
http://dri.sourceforge.net/doc/
For specific information about kernel-level support, see:
The Direct Rendering Manager, Kernel Support for the Direct Rendering
Infrastructure
http://dri.sourceforge.net/doc/drm_low_level.html
Hardware Locking for the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/hardware_locking_low_level.html
A Security Analysis of the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/security_low_level.html
f7bacf195e