Imre Deak 2dd2a883aa drm/i915: avoid processing spurious/shared interrupts in low-power states ... Atm, it's possible that the interrupt handler is called when the device is in D3 or some other low-power state. It can be due to another device that is still in D0 state and shares the interrupt line with i915, or on some platforms there could be spurious interrupts even without sharing the interrupt line. The latter case was reported by Klaus Ethgen using a Lenovo x61p machine (gen 4). He noticed this issue via a system suspend/resume hang and bisected it to the following commit: commit e11aa36230 Author: Jesse Barnes <jbarnes@virtuousgeek.org> Date: Wed Jun 18 09:52:55 2014 -0700 drm/i915: use runtime irq suspend/resume in freeze/thaw This is a problem, since in low-power states IIR will always read 0xffffffff resulting in an endless IRQ servicing loop. Fix this by handling interrupts only when the driver explicitly enables them and so it's guaranteed that the interrupt registers return a valid value. Note that this issue existed even before the above commit, since during runtime suspend/resume we never unregistered the handler. v2: - clarify the purpose of smp_mb() vs. synchronize_irq() in the code comment (Chris) v3: - no need for an explicit smp_mb(), we can assume that synchronize_irq() and the mmio read/writes in the install hooks provide for this (Daniel) - remove code comment as the remaining synchronize_irq() is self explanatory (Daniel) v4: - drm_irq_uninstall() implies synchronize_irq(), so no need to call it explicitly (Daniel) Reference: https://lkml.org/lkml/2015/2/11/205 Reported-and-bisected-by: Klaus Ethgen <Klaus@Ethgen.ch> Cc: stable@vger.kernel.org Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com>		2015-02-24 15:47:17 +02:00
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drm	drm/i915: avoid processing spurious/shared interrupts in low-power states	2015-02-24 15:47:17 +02:00
host1x	gpu: host1x: Provide a proper struct bus_type	2015-01-27 10:09:14 +01:00
ipu-v3	imx-drm fixes for IPUv3 DC and i.MX5 IPUv3 IC and TVE	2015-02-11 15:35:26 +10:00
vga	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-10-13 16:23:15 +02:00
Makefile	gpu: host1x: Provide a proper struct bus_type	2015-01-27 10:09:14 +01:00