On Fri, Aug 17, 2012 at 04:03:15AM +0100, Ben Hutchings wrote: > 3.2-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Daniel Vetter <[email protected]> > > commit 0d8957c8a90bbb5d34fab9a304459448a5131e06 upstream. > > We may only start to set up the new register values after having > confirmed that the ring is truely off. Otherwise the hw might lose the > newly written register values. This is caught later on in the init > sequence, when we check whether the register writes have stuck. > > Reviewed-by: Jani Nikula <[email protected]> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50522 > Tested-by: Yang Guang <[email protected]> > Signed-off-by: Daniel Vetter <[email protected]> > Signed-off-by: Ben Hutchings <[email protected]> [...]
With this commit on 3.2, i915 fails to initialize on a G41 based machine I have here: [ 36.894261] i915 0000:00:02.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16 [ 36.894265] i915 0000:00:02.0: setting latency timer to 64 [ 36.933118] mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining [ 36.933121] [drm] MTRR allocation failed. Graphics performance may suffer. [ 36.933467] i915 0000:00:02.0: irq 42 for MSI/MSI-X [ 36.933471] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010). [ 36.933472] [drm] Driver supports precise vblank timestamp query. [ 36.933498] vgaarb: device changed decodes: PCI:0000:00:02.0,olddecodes=io+mem,decodes=io+mem:owns=io+mem [ 36.969669] [drm:init_ring_common] *ERROR* render ring initialization failed ctl 0001f001 head 00001074 tail 00000000 start 00001000 [ 36.969763] vga_switcheroo: disabled [ 36.969765] [drm:i915_driver_load] *ERROR* failed to init modeset [ 36.987444] i915 0000:00:02.0: PCI INT A disabled [ 36.987453] i915: probe of 0000:00:02.0 failed with error -5 Taking a look at it, I suspected of a timing issue, especially looking at this commit, which isn't on 3.2: commit f01db988ef6f6c70a6cc36ee71e4a98a68901229 Author: Sean Paul <[email protected]> Date: Fri Mar 16 12:43:22 2012 -0400 drm/i915: Add wait_for in init_ring_common And picking it made the issue go away, so the extra delay helped and is needed with 0d8957c8a90bbb5d34fab9a304459448a5131e06 applied here. -- []'s Herton -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
