[PATCH 3.11 177/233] i915: remove pm_qos request on error

[Luis Henriques]

3.11.10.4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>

commit 22accca01713b13dac386ca90b787aadf88f6551 upstream.

Not removing pm qos request and free memory for it can cause crash,
when some other driver use pm qos. For example, this oops:

BUG: unable to handle kernel paging request at fffffffffffffff8
IP: [<ffffffff81307a6b>] plist_add+0x5b/0xd0
Call Trace:
 [<ffffffff810acf25>] pm_qos_update_target+0x125/0x1e0
 [<ffffffff810ad071>] pm_qos_add_request+0x91/0x100
 [<ffffffffa053ec14>] e1000_open+0xe4/0x5b0 [e1000e]

was caused by earlier i915 probe failure:

[drm:i915_report_and_clear_eir] *ERROR* EIR stuck: 0x00000010, masking
[drm:init_ring_common] *ERROR* render ring initialization failed ctl 0001f001 head 00003004 tail 00000000 start 00003000
[drm:i915_driver_load] *ERROR* failed to init modeset
i915: probe of 0000:00:02.0 failed with error -5

Bug report:
http://bugzilla.redhat.com/show_bug.cgi?id=1057533

Reported-by: Giandomenico De Tullio <ghisha@xxxxxxxxx>
Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
[danvet: Drop unnecessary code movement.]
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/i915/i915_dma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 0c956e9..58c3db8 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1675,6 +1675,7 @@ out_gem_unload:
 
 	intel_teardown_gmbus(dev);
 	intel_teardown_mchbar(dev);
+	pm_qos_remove_request(&dev_priv->pm_qos);
 	destroy_workqueue(dev_priv->wq);
 out_mtrrfree:
 	arch_phys_wc_del(dev_priv->mm.gtt_mtrr);
-- 
1.8.3.2

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