From: Stephen Rothwell <sfr@canb.auug.org.au> To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>, Peter Zijlstra <peterz@infradead.org>, Daniel Vetter <daniel.vetter@ffwll.ch>, <intel-gfx@lists.freedesktop.org>, <dri-devel@lists.freedesktop.org> Cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Wilson <chris@chris-wilson.co.uk> Subject: linux-next: build failure after merge of the tip tree (from the drm-intel tree) Date: Tue, 5 Jul 2016 13:53:03 +1000 [thread overview] Message-ID: <20160705135303.6a1bc80a@canb.auug.org.au> (raw) Hi all, After merging the tip tree, today's linux-next build (x86_64 allmodconfig) failed like this: In file included from include/uapi/linux/stddef.h:1:0, from include/linux/stddef.h:4, from include/uapi/linux/posix_types.h:4, from include/uapi/linux/types.h:13, from include/linux/types.h:5, from include/linux/sysrq.h:18, from drivers/gpu/drm/i915/i915_irq.c:31: drivers/gpu/drm/i915/i915_irq.c: In function 'i915_hangcheck_elapsed': include/linux/compiler.h:542:50: error: incompatible types when initializing type 'const void * const' using type 'bool {aka _Bool}' __maybe_unused const void * const _________p2 = _________p1; \ ^ drivers/gpu/drm/i915/i915_irq.c:3098:7: note: in expansion of macro 'lockless_dereference' if (!lockless_dereference(dev_priv->gt.awake)) ^ Caused by commit 67d97da34917 ("drm/i915: Only start retire worker when idle") from the drm-intel tree interacting with commit 331b6d8c7afc ("locking/barriers: Validate lockless_dereference() is used on a pointer type") from the tip tree. >From include/linux/compiler.h: * lockless_dereference() - safely load a pointer for later dereference * @p: The pointer to load It looks like lockless_dererence() has been used incorrectly in the drm-intel tree commit since its argument must be a pointer to be dererenced later. The same thing is done in drivers/gpu/drm/i915/i915_gem.c as well. I have applied the following hack patch for now, but this needs to be fixed properly. From: Stephen Rothwell <sfr@canb.auug.org.au> Date: Tue, 5 Jul 2016 13:44:39 +1000 Subject: [PATCH] drm/i915: hack around bad use of lockless_dereference() Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> --- drivers/gpu/drm/i915/i915_gem.c | 2 +- drivers/gpu/drm/i915/i915_irq.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index d3502c0603e5..1f91f187b2a8 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3290,7 +3290,7 @@ i915_gem_retire_work_handler(struct work_struct *work) * We do not need to do this test under locking as in the worst-case * we queue the retire worker once too often. */ - if (lockless_dereference(dev_priv->gt.awake)) + if (/*lockless_dereference*/(dev_priv->gt.awake)) queue_delayed_work(dev_priv->wq, &dev_priv->gt.retire_work, round_jiffies_up_relative(HZ)); diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index f6de8dd567a2..2c1926418691 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -3095,7 +3095,7 @@ static void i915_hangcheck_elapsed(struct work_struct *work) if (!i915.enable_hangcheck) return; - if (!lockless_dereference(dev_priv->gt.awake)) + if (!/*lockless_dereference*/(dev_priv->gt.awake)) return; /* As enabling the GPU requires fairly extensive mmio access, -- 2.8.1 -- Cheers, Stephen Rothwell
WARNING: multiple messages have this Message-ID (diff)
From: Stephen Rothwell <sfr@canb.auug.org.au> To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>, Peter Zijlstra <peterz@infradead.org>, Daniel Vetter <daniel.vetter@ffwll.ch>, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Wilson <chris@chris-wilson.co.uk> Subject: linux-next: build failure after merge of the tip tree (from the drm-intel tree) Date: Tue, 5 Jul 2016 13:53:03 +1000 [thread overview] Message-ID: <20160705135303.6a1bc80a@canb.auug.org.au> (raw) Hi all, After merging the tip tree, today's linux-next build (x86_64 allmodconfig) failed like this: In file included from include/uapi/linux/stddef.h:1:0, from include/linux/stddef.h:4, from include/uapi/linux/posix_types.h:4, from include/uapi/linux/types.h:13, from include/linux/types.h:5, from include/linux/sysrq.h:18, from drivers/gpu/drm/i915/i915_irq.c:31: drivers/gpu/drm/i915/i915_irq.c: In function 'i915_hangcheck_elapsed': include/linux/compiler.h:542:50: error: incompatible types when initializing type 'const void * const' using type 'bool {aka _Bool}' __maybe_unused const void * const _________p2 = _________p1; \ ^ drivers/gpu/drm/i915/i915_irq.c:3098:7: note: in expansion of macro 'lockless_dereference' if (!lockless_dereference(dev_priv->gt.awake)) ^ Caused by commit 67d97da34917 ("drm/i915: Only start retire worker when idle") from the drm-intel tree interacting with commit 331b6d8c7afc ("locking/barriers: Validate lockless_dereference() is used on a pointer type") from the tip tree. >From include/linux/compiler.h: * lockless_dereference() - safely load a pointer for later dereference * @p: The pointer to load It looks like lockless_dererence() has been used incorrectly in the drm-intel tree commit since its argument must be a pointer to be dererenced later. The same thing is done in drivers/gpu/drm/i915/i915_gem.c as well. I have applied the following hack patch for now, but this needs to be fixed properly. From: Stephen Rothwell <sfr@canb.auug.org.au> Date: Tue, 5 Jul 2016 13:44:39 +1000 Subject: [PATCH] drm/i915: hack around bad use of lockless_dereference() Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> --- drivers/gpu/drm/i915/i915_gem.c | 2 +- drivers/gpu/drm/i915/i915_irq.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index d3502c0603e5..1f91f187b2a8 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3290,7 +3290,7 @@ i915_gem_retire_work_handler(struct work_struct *work) * We do not need to do this test under locking as in the worst-case * we queue the retire worker once too often. */ - if (lockless_dereference(dev_priv->gt.awake)) + if (/*lockless_dereference*/(dev_priv->gt.awake)) queue_delayed_work(dev_priv->wq, &dev_priv->gt.retire_work, round_jiffies_up_relative(HZ)); diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index f6de8dd567a2..2c1926418691 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -3095,7 +3095,7 @@ static void i915_hangcheck_elapsed(struct work_struct *work) if (!i915.enable_hangcheck) return; - if (!lockless_dereference(dev_priv->gt.awake)) + if (!/*lockless_dereference*/(dev_priv->gt.awake)) return; /* As enabling the GPU requires fairly extensive mmio access, -- 2.8.1 -- Cheers, Stephen Rothwell
next reply other threads:[~2016-07-05 3:53 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-07-05 3:53 Stephen Rothwell [this message] 2016-07-05 3:53 ` linux-next: build failure after merge of the tip tree (from the drm-intel tree) Stephen Rothwell 2016-07-05 8:25 ` Peter Zijlstra 2016-07-05 8:25 ` Peter Zijlstra 2016-07-05 17:59 ` Paul E. McKenney
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