On Thu, Apr 17, 2014 at 12:26:37PM -0600, Bjorn Helgaas wrote: > Thanks a lot for testing this out and debugging my issues. > > Here's a new version that looks for both device IDs I know about. I can confirm this patch does fix the backtrace. I disabled lockdep, and now I can get to X each boot, but I still see a black screen rather than a console between modesetting becoming active, and X starting. (The lockdep thing turned out to be a known XFS false positive, but for some reason it actually caused X to lock up) > I'm still nervous about the modeset problem Dave is seeing. Since the > original patch wouldn't find an 8086:0c00 device on Dave's system, it > should have done nothing. But since it caused a modesetting problem, > there's something else doing on that I don't understand. I don't know if it's relevant, but this laptop (and I suspect many other thinkpads which seem affected) have dual gfx, both show up on the bus, even if though the nvidia isn't in use.. 00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) (prog-if 00 [VGA controller]) Subsystem: Lenovo Device 2200 Flags: bus master, fast devsel, latency 0, IRQ 44 Memory at f1000000 (64-bit, non-prefetchable) [size=4M] Memory at e0000000 (64-bit, prefetchable) [size=256M] I/O ports at 6000 [size=64] Expansion ROM at <unassigned> [disabled] Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [d0] Power Management version 2 Capabilities: [a4] PCI Advanced Features Kernel driver in use: i915 01:00.0 3D controller: NVIDIA Corporation GF117M [GeForce 610M/710M/820M / GT 620M/625M/630M/720M] (rev a1) Subsystem: Lenovo NVS 5200M Flags: bus master, fast devsel, latency 0, IRQ 11 Memory at f0000000 (32-bit, non-prefetchable) [size=16M] Memory at c0000000 (64-bit, prefetchable) [size=256M] Memory at d0000000 (64-bit, prefetchable) [size=32M] I/O ports at 5000 [size=128] Expansion ROM at <ignored> [disabled] Capabilities: [60] Power Management version 3 Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+ Capabilities: [78] Express Endpoint, MSI 00 Capabilities: [b4] Vendor Specific Information: Len=14 <?> Capabilities: [100] Virtual Channel Capabilities: [128] Power Budgeting <?> Capabilities: [600] Vendor Specific Information: ID=0001 Rev=1 Len=024 <?> Just as X starts up, I see this in dmesg.. [ 42.879049] [drm:cpt_serr_int_handler] *ERROR* PCH transcoder A FIFO underrun Dave -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html