On Sat, Aug 18, 2012 at 1:29 AM, Herton Ronaldo Krzesinski <[email protected]> wrote: > 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.
Good catch, I've forgotten to check whether all the recent ring_init patches have gone through cc: stable. For the stable team, please pick up both patches: f01db988ef6f6c70a6cc36ee71e4a98a68901229 and 0d8957c8a90bbb5d34fab9a304459448a5131e06 Note that all kernels that need f01db backported also need b7884eb45ec98c0d34c7f49005ae9d4b4b4e38f6 (to fix a regression introduce by the former). Yeah, the ring init sequence is a fickle beast :( but I'm pretty sure with these three patches, stable kernels should be up to date and have all the latest fixes. Yours, Daniel -- Daniel Vetter [email protected] - +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- 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/
