From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754248AbcGEDxJ (ORCPT ); Mon, 4 Jul 2016 23:53:09 -0400 Received: from ozlabs.org ([103.22.144.67]:47957 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753602AbcGEDxH convert rfc822-to-8bit (ORCPT ); Mon, 4 Jul 2016 23:53:07 -0400 Date: Tue, 5 Jul 2016 13:53:03 +1000 From: Stephen Rothwell To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Peter Zijlstra , Daniel Vetter , , Cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Wilson Subject: linux-next: build failure after merge of the tip tree (from the drm-intel tree) Message-ID: <20160705135303.6a1bc80a@canb.auug.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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 --- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Rothwell 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 Message-ID: <20160705135303.6a1bc80a@canb.auug.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Return-path: Received: from ozlabs.org ([103.22.144.67]:47957 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753602AbcGEDxH convert rfc822-to-8bit (ORCPT ); Mon, 4 Jul 2016 23:53:07 -0400 Sender: linux-next-owner@vger.kernel.org List-ID: To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Peter Zijlstra , Daniel Vetter , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Wilson 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 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 --- 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