linux_dsm_epyc7002/drivers/gpu/drm
Daniel Vetter b6c5164d7b drm/i915: Fixup Oops in the pipe config computation
Yet again our current confusion between doing the modeset globally,
but only having the new parameters for one crtc at a time.

So that intel_set_mode essentially already does a global modeset:
intel_modeset_affected_pipes compares the current state with where we
want to go to (which is carefully set up by intel_crtc_set_config) and
then goes through the modeset sequence for any crtc which needs
updating.

Now the issue is that the actual interface with the remaining code
still only works on one crtc, and so we only pass in one fb and one
mode. In intel_set_mode we also only compute one intel_crtc_config
(which should be the one for the crtc we're doing a modeset on).

The reason for that mismatch is twofold:
- We want to eventually do all modeset as global state changes, so
it's just infrastructure prep.
- But even the old semantics can change more than one crtc when you
e.g. move a connector from crtc A to crtc B, then both crtc A and B
need to be updated. Usually that means one pipe is disabled and the
other enabled. This is also the reason why the hack doesn't touch the
disable_pipes mask.

Now hilarity ensued in our kms config restore paths when we actually
try to do a modeset on all crtcs: If the first crtc should be off and
the second should be on, then the call on the first crtc will notice
that the 2nd one should be switched on and so tries to compute the
pipe_config. But due to a lack of passed-in fb (crtc 1 should be off
after all) it only results in tears.

This case is ridiculously easy to hit on gen2/3 where the lvds output
is restricted to pipe B. Note that before the pipe_config bpp rework
gen2/3 didn't care really about the fb->depth, so this is a regression
brought to light with

commit 4e53c2e010
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Mar 27 00:44:58 2013 +0100

    drm/i915: precompute pipe bpp before touching the hw

But apparently Ajax also managed to blow up pch platforms, probably
with some randomized configs, and pch platforms trip up over the lack
of an fb even in the old code. So this actually goes back to the first
introduction of the new modeset restore code in

commit 45e2b5f640
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Nov 23 18:16:34 2012 +0100

    drm/i915: force restore on lid open

Fix this mess by now by justing shunting all the cool new global
modeset logic in intel_modeset_affected_pipes.

v2: Improve commit message and clean up all the comments in
intel_modeset_affected_pipes - since the introduction of the modeset
restore code they've been a bit outdated.

Bugzill: https://bugzilla.redhat.com/show_bug.cgi?id=917725
Cc: stable@vger.kernel.org
References: http://www.mail-archive.com/stable@vger.kernel.org/msg38084.html
Tested-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-04-18 09:43:24 +02:00
..
ast Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2013-02-25 16:46:44 -08:00
cirrus Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2013-02-25 16:46:44 -08:00
exynos drm/exynos: Check g2d cmd list for g2d restrictions 2013-03-20 19:09:11 +09:00
gma500 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
i2c drm/i2c: nxp-tda998x (v3) 2013-02-19 17:57:44 -05:00
i810
i915 drm/i915: Fixup Oops in the pipe config computation 2013-04-18 09:43:24 +02:00
mga
mgag200 drm/mgag200: Bug fix: Modified pll algorithm for EH project 2013-03-21 10:16:58 +10:00
nouveau drm/nv50/kms: prevent lockdep false-positive in page flipping path 2013-03-19 15:26:38 +10:00
omapdrm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
r128
radeon drm/radeon: add support for Richland APUs 2013-03-15 18:47:19 -04:00
savage
shmobile drm/shmobile: use drm_modeset_lock_all 2013-01-20 22:16:51 +01:00
sis drm/sis: convert to idr_alloc() 2013-02-27 19:10:16 -08:00
tdfx
tegra drm/tegra: drop "select DRM_HDMI" 2013-03-08 08:36:01 +10:00
tilcdc drm/tilcdc: only build on arm 2013-02-26 09:54:48 +10:00
ttm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
udl Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
via drm/via: convert to idr_alloc() 2013-02-27 19:10:16 -08:00
vmwgfx drm/vmwgfx: convert to idr_alloc() 2013-02-27 19:10:16 -08:00
ati_pcigart.c
drm_agpsupport.c
drm_auth.c
drm_buffer.c
drm_bufs.c
drm_cache.c lib/scatterlist: sg_page_iter: support sg lists w/o backing pages 2013-03-27 17:13:44 +01:00
drm_context.c drm: convert to idr_alloc() 2013-02-27 19:10:15 -08:00
drm_crtc_helper.c drm: don't hold crtc mutexes for connector ->detect callbacks 2013-01-20 22:17:15 +01:00
drm_crtc.c drm: convert to idr_alloc() 2013-02-27 19:10:15 -08:00
drm_debugfs.c
drm_dma.c
drm_dp_helper.c
drm_drv.c drm: don't use idr_remove_all() 2013-02-27 19:10:13 -08:00
drm_edid_load.c
drm_edid.c KMS: fix EDID detailed timing frame rate 2013-03-23 10:46:10 -07:00
drm_encoder_slave.c drm: i2c encoder helper wrappers 2013-02-17 17:55:42 -05:00
drm_fb_cma_helper.c Merge branch 'tilcdc-next' of git://people.freedesktop.org/~robclark/linux into drm-next 2013-02-21 09:31:47 +10:00
drm_fb_helper.c drm: add initial_config function to fb helper 2013-03-26 21:32:53 +01:00
drm_fops.c drm: revamp locking around fb creation/destruction 2013-01-20 22:16:58 +01:00
drm_gem_cma_helper.c drm/cma: add debugfs helpers 2013-02-17 17:55:42 -05:00
drm_gem.c drm: convert to idr_alloc() 2013-02-27 19:10:15 -08:00
drm_global.c
drm_hashtab.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
drm_info.c
drm_ioc32.c
drm_ioctl.c
drm_irq.c drm: small fix in drm_send_vblank_event() 2013-02-17 17:55:42 -05:00
drm_lock.c
drm_memory.c
drm_mm.c Merge branch 'drm-kms-locking' of git://people.freedesktop.org/~danvet/drm-intel into drm-next 2013-01-21 07:44:58 +10:00
drm_modes.c drm_modes: add of_videomode helpers 2013-01-24 09:04:14 +01:00
drm_pci.c drm/pci: define drm_pcie_get_speed_cap_mask() only when CONFIG_PCI=y 2013-02-15 10:15:19 +10:00
drm_platform.c
drm_prime.c drm: modify pages_to_sg prime helper to create optimized SG table 2013-03-23 12:17:57 +01:00
drm_proc.c
drm_scatter.c
drm_stub.c drm: convert to idr_alloc() 2013-02-27 19:10:15 -08:00
drm_sysfs.c
drm_trace_points.c
drm_trace.h
drm_usb.c drm/usb: bind driver to correct device 2013-02-07 12:37:41 +10:00
drm_vm.c
Kconfig drm: Add HDMI infoframe helpers 2013-02-22 08:20:10 +01:00
Makefile Merge branch 'tilcdc-next' of git://people.freedesktop.org/~robclark/linux into drm-next 2013-02-21 09:31:47 +10:00
README.drm

************************************************************
* 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