9f1f46a45a
The problem this patch solves is that the forcewake accounting necessary for register reads is protected by dev->struct_mutex. But the hangcheck and error_capture code need to access registers without grabbing this mutex because we hold it while waiting for the gpu. So a new lock is required. Because currently the error_state capture is called from the error irq handler and the hangcheck code runs from a timer, it needs to be an irqsafe spinlock (note that the registers used by the irq handler (neglecting the error handling part) only uses registers that don't need the forcewake dance). We could tune this down to a normal spinlock when we rework the error_state capture and hangcheck code to run from a workqueue. But we don't have any read in a fastpath that needs forcewake, so I've decided to not care much about overhead. This prevents tests/gem_hangcheck_forcewake from i-g-t from killing my snb on recent kernels - something must have slightly changed the timings. On previous kernels it only trigger a WARN about the broken locking. v2: Drop the previous patch for the register writes. v3: Improve the commit message per Chris Wilson's suggestions. Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com> Signed-off-by: Keith Packard <keithp@keithp.com> |
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|---|---|---|
| .. | ||
| exynos | ||
| gma500 | ||
| i2c | ||
| i810 | ||
| i915 | ||
| mga | ||
| nouveau | ||
| r128 | ||
| radeon | ||
| savage | ||
| sis | ||
| tdfx | ||
| ttm | ||
| via | ||
| vmwgfx | ||
| Kconfig | ||
| Makefile | ||
| README.drm | ||
| ati_pcigart.c | ||
| drm_agpsupport.c | ||
| drm_auth.c | ||
| drm_buffer.c | ||
| drm_bufs.c | ||
| drm_cache.c | ||
| drm_context.c | ||
| drm_crtc.c | ||
| drm_crtc_helper.c | ||
| drm_debugfs.c | ||
| drm_dma.c | ||
| drm_dp_i2c_helper.c | ||
| drm_drv.c | ||
| drm_edid.c | ||
| drm_edid_modes.h | ||
| drm_encoder_slave.c | ||
| drm_fb_helper.c | ||
| drm_fops.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_proc.c | ||
| drm_scatter.c | ||
| drm_stub.c | ||
| drm_sysfs.c | ||
| drm_trace.h | ||
| drm_trace_points.c | ||
| drm_usb.c | ||
| drm_vm.c | ||
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