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@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Stanislaw Gruszka sgruszka@redhat.com --- drivers/gpu/drm/i915/i915_dma.c | 4 ++++ drivers/gpu/drm/i915/i915_irq.c | 2 -- 2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 5c64842..e141a32 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1603,6 +1603,9 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags) goto out_mtrrfree; }
+ pm_qos_add_request(&dev_priv->pm_qos, PM_QOS_CPU_DMA_LATENCY, + PM_QOS_DEFAULT_VALUE); + intel_irq_init(dev); intel_uncore_sanitize(dev);
@@ -1679,6 +1682,7 @@ 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->gtt.mtrr); diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 5d1dedc..09e268a 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -3784,8 +3784,6 @@ void intel_irq_init(struct drm_device *dev) setup_timer(&dev_priv->hotplug_reenable_timer, i915_reenable_hotplug_timer_func, (unsigned long) dev_priv);
- pm_qos_add_request(&dev_priv->pm_qos, PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE); - if (IS_GEN2(dev)) { dev->max_vblank_count = 0; dev->driver->get_vblank_counter = i8xx_get_vblank_counter;