linux/drivers/gpu/drm
Mika Kuoppala 05407ff889 drm/i915: detect hang using per ring hangcheck_score
Keep track of ring seqno progress and if there are no
progress detected, declare hang. Use actual head (acthd)
to distinguish between ring stuck and batchbuffer looping
situation. Stuck ring will be kicked to trigger progress.

This commit adds a hard limit for batchbuffer completion time.
If batchbuffer completion time is more than 4.5 seconds,
the gpu will be declared hung.

Review comment from Ben which nicely clarifies the semantic change:

"Maybe I'm just stating the functional changes of the patch, but in case
they were unintended here is what I see as potential issues:

1. "If ring B is waiting on ring A via semaphore, and ring A is making
   progress, albeit slowly - the hangcheck will fire. The check will
   determine that A is moving, however ring B will appear hung because
   the ACTHD doesn't move. I honestly can't say if that's actually a
   realistic problem to hit it probably implies the timeout value is too
   low.

2. "There's also another corner case on the kick. If the seqno = 2
   (though not stuck), and on the 3rd hangcheck, the ring is stuck, and
   we try to kick it... we don't actually try to find out if the kick
   helped"

v2: use atchd to detect stuck ring from loop (Ben Widawsky)

v3: Use acthd to check when ring needs kicking.
Declare hang on third time in order to give time for
kick_ring to take effect.

v4: Update commit msg

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: Paste in Ben's review comment.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-06-03 10:58:21 +02:00
..
ast
cirrus
exynos
gma500
i2c
i810
i915 drm/i915: detect hang using per ring hangcheck_score 2013-06-03 10:58:21 +02:00
mga
mgag200
nouveau
omapdrm
qxl
r128
radeon
savage
shmobile
sis
tdfx
tilcdc
ttm
udl
via
vmwgfx
ati_pcigart.c
drm_agpsupport.c
drm_auth.c
drm_buffer.c
drm_bufs.c
drm_cache.c
drm_context.c
drm_crtc_helper.c
drm_crtc.c
drm_debugfs.c
drm_dma.c
drm_dp_helper.c
drm_drv.c
drm_edid_load.c
drm_edid.c
drm_encoder_slave.c
drm_fb_cma_helper.c
drm_fb_helper.c
drm_fops.c
drm_gem_cma_helper.c
drm_gem.c
drm_global.c
drm_hashtab.c
drm_info.c
drm_ioc32.c
drm_ioctl.c
drm_irq.c
drm_lock.c
drm_memory.c
drm_mm.c
drm_modes.c
drm_pci.c
drm_platform.c
drm_prime.c
drm_proc.c
drm_rect.c
drm_scatter.c
drm_stub.c
drm_sysfs.c
drm_trace_points.c
drm_trace.h
drm_usb.c
drm_vm.c
Kconfig
Makefile Linux 3.10-rc2 2013-05-21 09:52:16 +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