Chris Wilson 9ea8d05932 drm/i915: Hold struct mutex whilst pinning power context bo. ... Hugh found an error path where we were attempting to unref a bo without holding the struct mutex: [drm:intel_init_clock_gating] *ERROR* failed to pin power context: -16 ------------[ cut here ]------------ WARNING: at drivers/gpu/drm/drm_gem.c:438 drm_gem_object_free+0x20/0x5e() Hardware name: ESPRIMO Mobile V5505 Modules linked in: snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device Pid: 3793, comm: s2ram Not tainted 2.6.33-rc2 #4 Call Trace: [<7815298e>] warn_slowpath_common+0x59/0x6b [<781529b3>] warn_slowpath_null+0x13/0x18 [<78317c1a>] ? drm_gem_object_free+0x20/0x5e [<78317c1a>] drm_gem_object_free+0x20/0x5e [<78317bfa>] ? drm_gem_object_free+0x0/0x5e [<7829df11>] kref_put+0x38/0x45 [<7833a5f0>] intel_init_clock_gating+0x232/0x271 [<78317bfa>] ? drm_gem_object_free+0x0/0x5e [<7832c307>] i915_restore_state+0x21a/0x2b3 [<7832379d>] i915_resume+0x3c/0xbb [<78174fe5>] ? trace_hardirqs_on_caller+0xfc/0x123 [<7831c756>] ? drm_class_resume+0x0/0x3e [<7831c78d>] drm_class_resume+0x37/0x3e [<78351e0a>] legacy_resume+0x1e/0x51 [<78351ece>] device_resume+0x91/0xab [<7831c756>] ? drm_class_resume+0x0/0x3e [<78352226>] dpm_resume+0x58/0x10f [<783522fb>] dpm_resume_end+0x1e/0x2c [<78180f80>] suspend_devices_and_enter+0x61/0x84 [<78180ff8>] enter_state+0x55/0x83 [<7818091c>] state_store+0x94/0xaa [<7829d09e>] kobj_attr_store+0x1e/0x23 [<782098e0>] sysfs_write_file+0x66/0x99 [<781cd2f0>] vfs_write+0x8a/0x108 [<781cd408>] sys_write+0x3c/0x63 [<78125c10>] sysenter_do_call+0x12/0x36 ---[ end trace a343537f29950fda ]--- It is in fact slightly more insiduous that first appears since we are attempting to not just free the object without the lock, but are trying to do the whole bo manipulation without holding the lock. Reported-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: stable@kernel.org Signed-off-by: Eric Anholt <eric@anholt.net>		2010-01-06 09:40:10 -08:00
..
drm	drm/i915: Hold struct mutex whilst pinning power context bo.	2010-01-06 09:40:10 -08:00
vga	PCI/vgaarb: cleanup some warnings + cleanup some comments.	2009-09-09 13:29:41 -07:00
Makefile	PCI/GPU: implement VGA arbitration on Linux	2009-09-09 13:29:36 -07:00