linux/drivers/gpu/drm
Konrad Rzeszutek Wilk 426729dcc7 drm/i915: make compact dma scatter lists creation work with SWIOTLB backend.
Git commit 90797e6d1e
("drm/i915: create compact dma scatter lists for gem objects") makes
certain assumptions about the under laying DMA API that are not always
correct.

On a ThinkPad X230 with an Intel HD 4000 with Xen during the bootup
I see:

[drm:intel_pipe_set_base] *ERROR* pin & fence failed
[drm:intel_crtc_set_config] *ERROR* failed to set mode on [CRTC:3], err = -28

Bit of debugging traced it down to dma_map_sg failing (in
i915_gem_gtt_prepare_object) as some of the SG entries were huge (3MB).

That unfortunately are sizes that the SWIOTLB is incapable of handling -
the maximum it can handle is a an entry of 512KB of virtual contiguous
memory for its bounce buffer. (See IO_TLB_SEGSIZE).

Previous to the above mention git commit the SG entries were of 4KB, and
the code introduced by above git commit squashed the CPU contiguous PFNs
in one big virtual address provided to DMA API.

This patch is a simple semi-revert - were we emulate the old behavior
if we detect that SWIOTLB is online. If it is not online then we continue
on with the new compact scatter gather mechanism.

An alternative solution would be for the the '.get_pages' and the
i915_gem_gtt_prepare_object to retry with smaller max gap of the
amount of PFNs that can be combined together - but with this issue
discovered during rc7 that might be too risky.

Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: Chris Wilson <chris@chris-wilson.co.uk>
CC: Imre Deak <imre.deak@intel.com>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
CC: David Airlie <airlied@linux.ie>
CC: <dri-devel@lists.freedesktop.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-06-25 10:39:57 +10:00
..
ast drm/ast: deal with bo reserve fail in dirty update path 2013-05-02 12:46:47 +10:00
cirrus drm/cirrus: deal with bo reserve fail in dirty update path 2013-05-02 12:46:56 +10:00
exynos Merge branch 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-next 2013-05-24 10:14:57 +10:00
gma500 Merge branch 'gma500-fixes' of git://github.com/patjak/drm-gma500 into drm-fixes 2013-06-11 08:16:10 +10:00
i2c drm/i2c: nxp-tda998x (v3) 2013-02-19 17:57:44 -05:00
i810
i915 drm/i915: make compact dma scatter lists creation work with SWIOTLB backend. 2013-06-25 10:39:57 +10:00
mga
mgag200 drm/mgag200: Add missing write to index before accessing data register 2013-06-03 19:21:07 +10:00
nouveau Merge branch 'drm-nouveau-fixes-3.10' of git://anongit.freedesktop.org/git/nouveau/linux-2.6 into drm-fixes 2013-06-05 14:35:08 +10:00
omapdrm Merge branch 'fbdev-3.10-fixes' of git://gitorious.org/linux-omap-dss2/linux into linux-fbdev/for-3.10-fixes 2013-05-29 17:00:34 +08:00
qxl drm/qxl: fix build warnings on 32-bit 2013-05-31 12:45:09 +10:00
r128
radeon drm/radeon: update lockup tracking when scheduling in empty ring 2013-06-20 14:45:08 -04:00
savage
shmobile drm/shmob: use drm_send_vblank_event() helper 2013-05-22 09:13:41 +10:00
sis drm/sis: convert to idr_alloc() 2013-02-27 19:10:16 -08:00
tdfx
tilcdc drm/tilcd: select BACKLIGHT_LCD_SUPPORT 2013-06-03 19:20:49 +10:00
ttm drm: use vma_pages() to replace (vm_end - vm_start) >> PAGE_SHIFT 2013-04-16 13:14:00 +10:00
udl Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2013-05-02 19:40:34 -07:00
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: Only print a debug message when the polled connector has changed 2013-05-13 12:13:06 +10:00
drm_crtc.c drm: Make the HPD status updates debug logs more readable 2013-05-13 12:12:57 +10:00
drm_debugfs.c
drm_dma.c
drm_dp_helper.c
drm_drv.c drm: Use names of ioctls in debug traces 2013-05-10 14:46:50 +10:00
drm_edid_load.c drm: Add 1600x1200 (UXGA) screen resolution to the built-in EDIDs 2013-04-12 14:06:16 +10:00
drm_edid.c drm/edid: Check both 60Hz and 59.94Hz when looking for a CEA mode 2013-04-26 10:25:54 +10:00
drm_encoder_slave.c drm: refactor call to request_module 2013-05-10 14:46:03 +10:00
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 Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2013-05-02 19:40:34 -07:00
drm_fops.c drm: correctly restore mappings if drm_open fails 2013-04-03 06:44:38 +10:00
drm_gem_cma_helper.c drm/cma: add debugfs helpers 2013-02-17 17:55:42 -05:00
drm_gem.c drm/prime: keep a reference from the handle to exported dma-buf (v6) 2013-05-01 09:30:15 +10:00
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: fix a use-after-free when GPU acceleration disabled 2013-06-03 19:12:04 +10:00
drm_lock.c
drm_memory.c
drm_mm.c drm/mm: fix dump table BUG 2013-04-30 15:15:58 +02:00
drm_modes.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2013-05-13 07:59:59 -07:00
drm_pci.c drm: Silence some sparse warnings 2013-04-30 10:02:25 +10:00
drm_platform.c
drm_prime.c drm/prime: Honor requested file flags when exporting a buffer 2013-06-19 11:34:54 +10:00
drm_proc.c drm: proc: Use remove_proc_subtree() 2013-05-01 17:29:44 -04:00
drm_scatter.c
drm_stub.c drm: proc: Use minor->index to label things, not PDE->name 2013-05-01 17:29:44 -04:00
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 drm: export drm_vm_open_locked 2013-04-26 10:20:00 +10:00
Kconfig drm/tegra: Move drm to live under host1x 2013-04-22 12:39:11 +02:00
Makefile drm/tegra: Move drm to live under host1x 2013-04-22 12:39:11 +02:00
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