diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2014-04-25 22:11:51 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2014-05-05 09:09:18 +0200 |
| commit | 8a6543ba4719ff940b22ce9f9830a9c3fd9e1b60 (patch) | |
| tree | 5d2b965931131299d827ec1d14b6164663985113 | |
| parent | 713028b3ce1d5eab1b3a69857561582613308e46 (diff) | |
drm/i915: Fix deadlock during driver init on ILK
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 <imre.deak@intel.com>
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 <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
| -rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 4717ddbbfe2d..423f44ba2b43 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -11252,9 +11252,7 @@ void intel_modeset_init_hw(struct drm_device *dev) intel_reset_dpio(dev); - mutex_lock(&dev->struct_mutex); intel_enable_gt_powersave(dev); - mutex_unlock(&dev->struct_mutex); } void intel_modeset_suspend_hw(struct drm_device *dev) |