On Fri, Apr 25, 2014 at 10:11:51PM +0300, [email protected] wrote: > From: Ville Syrjälä <[email protected]> > > We have a struct_mutex deadlock during driver init on ILK > > [ 54.320273] ============================================= > [ 54.320371] [ INFO: possible recursive locking detected ] > [ 54.320471] 3.15.0-rc2-flip_race+ #2 Not tainted > [ 54.320567] --------------------------------------------- > [ 54.320665] modprobe/2178 is trying to acquire lock: > [ 54.320762] (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa0568b05>] > intel_enable_gt_powersave+0xa5/0x9d0 [i915] > [ 54.321111] > [ 54.321111] but task is already holding lock: > [ 54.321250] (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa05b4c2e>] > intel_modeset_init_hw+0x3e/0x60 [i915] > [ 54.321583] > [ 54.321583] other info that might help us debug this: > [ 54.321724] Possible unsafe locking scenario: > [ 54.321724] > [ 54.321863] CPU0 > [ 54.321954] ---- > [ 54.322046] lock(&dev->struct_mutex); > [ 54.322221] lock(&dev->struct_mutex); > [ 54.322397] > [ 54.322397] *** DEADLOCK *** > [ 54.322397] > [ 54.322638] May be due to missing lock nesting notation > [ 54.322638] > [ 54.322781] 4 locks held by modprobe/2178: > [ 54.322875] #0: (&dev->mutex){......}, at: [<ffffffff813592eb>] > __driver_attach+0x5b/0xb0 > [ 54.323230] #1: (&dev->mutex){......}, at: [<ffffffff813592f9>] > __driver_attach+0x69/0xb0 > [ 54.323582] #2: (drm_global_mutex){+.+.+.}, at: [<ffffffffa04e1e0d>] > drm_dev_register+0x2d/0x120 [drm] > [ 54.323945] #3: (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa05b4c2e>] > intel_modeset_init_hw+0x3e/0x60 [i915] > > This regression got introduced in: > commit 586d5270b60dc1f35cc3ca982d403765bad77965 > Author: Imre Deak <[email protected]> > Date: Mon Apr 14 20:24:28 2014 +0300 > > drm/i915: move getting struct_mutex lower in the callstack during GPU > reset > > Fix the problem by not taking struct_mutex around intel_enable_gt_powersave() > in intel_modeset_init_hw() since intel_enable_gt_powersave() now grabs the > mutex itself. > > Signed-off-by: Ville Syrjälä <[email protected]>
Queued for -next, thanks for the patch. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
