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cef1d00cd5
Noticed that my old Radeon 7500 hung after printing drm: GPU not posted. posting now... when it wasn't selected as the primary card the BIOS. Some digging revealed that it was hanging in combios_parse_mmio_table() while parsing the ASIC INIT 3 table. Looking at the BIOS ROM for the card, it becomes obvious that there is no ASIC INIT 3 table in the BIOS. The code is just processing random garbage. No surprise it hangs! Why do I say that there is no ASIC INIT 3 table is the BIOS? This table is found through the MISC INFO table. The MISC INFO table can be found at offset 0x5e in the COMBIOS header. But the header is smaller than that. The COMBIOS header starts at offset 0x126. The standard PCI Data Structure (the bit that starts with 'PCIR') lives at offset 0x180. That means that the COMBIOS header can not be larger than 0x5a bytes and therefore cannot contain a MISC INFO table. I looked at a dozen or so BIOS images, some my own, some downloaded from: <http://www.techpowerup.com/vgabios/index.php?manufacturer=ATI&page=1> It is fairly obvious that the size of the COMBIOS header can be found at offset 0x6 of the header. Not sure if it is a 16-bit number or just an 8-bit number, but that doesn't really matter since the tables seems to be always smaller than 256 bytes. So I think combios_get_table_offset() should check if the requested table is present. This can be done by checking the offset against the size of the header. See the diff below. The diff is against the WIP OpenBSD codebase that roughly corresponds to Linux 3.8.13 at this point. But I don't think this bit of the code changed much since then. For what it is worth: Signed-off-by: Mark Kettenis <kettenis@openbsd.org> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org |
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.. | ||
ast | ||
cirrus | ||
exynos | ||
gma500 | ||
i2c | ||
i810 | ||
i915 | ||
mga | ||
mgag200 | ||
nouveau | ||
omapdrm | ||
qxl | ||
r128 | ||
radeon | ||
rcar-du | ||
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.c | ||
drm_crtc_helper.c | ||
drm_debugfs.c | ||
drm_dma.c | ||
drm_dp_helper.c | ||
drm_drv.c | ||
drm_edid.c | ||
drm_edid_load.c | ||
drm_encoder_slave.c | ||
drm_fb_cma_helper.c | ||
drm_fb_helper.c | ||
drm_fops.c | ||
drm_gem.c | ||
drm_gem_cma_helper.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.h | ||
drm_trace_points.c | ||
drm_usb.c | ||
drm_vm.c | ||
Kconfig | ||
Makefile | ||
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