[PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Nathan Chancellor]

This warning is disabled by default in scripts/Makefile.extrawarn when
W= is not provided but this Makefile adds -Wall after this warning is
disabled so it shows up in the build when it shouldn't:

In file included from drivers/gpu/drm/i915/intel_breadcrumbs.c:895:
drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c:350:34: error:
variable 'wq' is uninitialized when used within its own initialization
[-Werror,-Wuninitialized]
        DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
                                        ^~
./include/linux/wait.h:74:63: note: expanded from macro
'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
        struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
                               ~~~~                                  ^~~~
./include/linux/wait.h:72:33: note: expanded from macro
'__WAIT_QUEUE_HEAD_INIT_ONSTACK'
        ({ init_waitqueue_head(&name); name; })
                                       ^~~~
1 error generated.

This warning looks to be a false positive given that init_waitqueue_head
initializes name before it is used. Rather than disable the warning for
the full folder like commit 46e2068081e9 ("drm/i915: Disable some extra
clang warnings"), just disable it for the one problematic file because
it could be a useful warning for other cases.

Link: https://github.com/ClangBuiltLinux/linux/issues/220
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
 drivers/gpu/drm/i915/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 1c2857f13ad4..f36c420afb99 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -26,6 +26,7 @@ subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror
 
 # Fine grained warnings disable
 CFLAGS_i915_pci.o = $(call cc-disable-warning, override-init)
+CFLAGS_intel_breadcrumbs.o = $(call cc-disable-warning, uninitialized)
 CFLAGS_intel_fbdev.o = $(call cc-disable-warning, override-init)
 
 subdir-ccflags-y += \
-- 
2.19.1

✗ Fi.CI.SPARSE: warning for drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Patchwork]

== Series Details ==

Series: drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o
URL   : https://patchwork.freedesktop.org/series/51542/
State : warning

== Summary ==

$ dim sparse origin/drm-tip
Sparse version: v0.5.2
Commit: drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o
-
+./include/linux/mm.h:592:13: error: not a function <noident>
+./include/linux/mm.h:592:13: error: not a function <noident>
+./include/linux/mm.h:592:13: error: undefined identifier '__builtin_mul_overflow'
+./include/linux/mm.h:592:13: warning: call with no type!
+./include/linux/slab.h:631:13: error: not a function <noident>
+./include/linux/slab.h:631:13: error: undefined identifier '__builtin_mul_overflow'
+./include/linux/slab.h:631:13: warning: call with no type!
+./include/uapi/linux/perf_event.h:147:56: warning: cast truncates bits from constant value (8000000000000000 becomes 0)

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

✓ Fi.CI.BAT: success for drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Patchwork]

== Series Details ==

Series: drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o
URL   : https://patchwork.freedesktop.org/series/51542/
State : success

== Summary ==

= CI Bug Log - changes from CI_DRM_5037 -> Patchwork_10585 =

== Summary - SUCCESS ==

  No regressions found.

  External URL: https://patchwork.freedesktop.org/api/1.0/series/51542/revisions/1/mbox/

== Known issues ==

  Here are the changes found in Patchwork_10585 that come from known issues:

  === IGT changes ===

    ==== Issues hit ====

    igt@drv_getparams_basic@basic-eu-total:
      fi-skl-6770hq:      PASS -> DMESG-WARN (fdo#105541)

    igt@drv_selftest@live_sanitycheck:
      fi-glk-j4005:       PASS -> DMESG-WARN (fdo#107726)

    igt@kms_flip@basic-flip-vs-modeset:
      fi-glk-j4005:       PASS -> DMESG-WARN (fdo#106000)

    igt@prime_vgem@basic-fence-flip:
      fi-cfl-8700k:       PASS -> FAIL (fdo#104008)

    
    ==== Possible fixes ====

    igt@kms_flip@basic-flip-vs-dpms:
      fi-glk-j4005:       DMESG-WARN (fdo#106000) -> PASS +1

    igt@kms_frontbuffer_tracking@basic:
      fi-glk-j4005:       FAIL (fdo#103167) -> PASS

    igt@kms_pipe_crc_basic@suspend-read-crc-pipe-b:
      fi-byt-clapper:     FAIL (fdo#103191, fdo#107362) -> PASS

    
  fdo#103167 https://bugs.freedesktop.org/show_bug.cgi?id=103167
  fdo#103191 https://bugs.freedesktop.org/show_bug.cgi?id=103191
  fdo#104008 https://bugs.freedesktop.org/show_bug.cgi?id=104008
  fdo#105541 https://bugs.freedesktop.org/show_bug.cgi?id=105541
  fdo#106000 https://bugs.freedesktop.org/show_bug.cgi?id=106000
  fdo#107362 https://bugs.freedesktop.org/show_bug.cgi?id=107362
  fdo#107726 https://bugs.freedesktop.org/show_bug.cgi?id=107726


== Participating hosts (46 -> 44) ==

  Additional (1): fi-icl-u 
  Missing    (3): fi-ilk-m540 fi-byt-squawks fi-bsw-cyan 


== Build changes ==

    * Linux: CI_DRM_5037 -> Patchwork_10585

  CI_DRM_5037: e11750586cb6054bd319ad217cecd045febaacc5 @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_4694: ff8d1156723f235e82cb4fcfd2cd6e5a5bb211fa @ git://anongit.freedesktop.org/xorg/app/intel-gpu-tools
  Patchwork_10585: af9ae53ac686bf661bdc630f0aee4364a7a2f1c1 @ git://anongit.freedesktop.org/gfx-ci/linux


== Linux commits ==

af9ae53ac686 drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_10585/issues.html
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Nick Desaulniers]

On Thu, Oct 25, 2018 at 12:36 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> This warning is disabled by default in scripts/Makefile.extrawarn when
> W= is not provided but this Makefile adds -Wall after this warning is
> disabled so it shows up in the build when it shouldn't:
>
> In file included from drivers/gpu/drm/i915/intel_breadcrumbs.c:895:
> drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c:350:34: error:
> variable 'wq' is uninitialized when used within its own initialization
> [-Werror,-Wuninitialized]
>         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
>                                         ^~
> ./include/linux/wait.h:74:63: note: expanded from macro
> 'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
>         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
>                                ~~~~                                  ^~~~
> ./include/linux/wait.h:72:33: note: expanded from macro
> '__WAIT_QUEUE_HEAD_INIT_ONSTACK'
>         ({ init_waitqueue_head(&name); name; })
>                                        ^~~~
> 1 error generated.
>
> This warning looks to be a false positive given that init_waitqueue_head
> initializes name before it is used. Rather than disable the warning for
> the full folder like commit 46e2068081e9 ("drm/i915: Disable some extra

cc author/reviewer of 46e2068081e9.

I'm fine with the patch as is, unless others prefer to disable it for
the whole subdir?  We could be playing whack-a-mole in the future
disabling this warning for other translation units.

> clang warnings"), just disable it for the one problematic file because
> it could be a useful warning for other cases.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/220
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
>  drivers/gpu/drm/i915/Makefile | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 1c2857f13ad4..f36c420afb99 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -26,6 +26,7 @@ subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror
>
>  # Fine grained warnings disable
>  CFLAGS_i915_pci.o = $(call cc-disable-warning, override-init)
> +CFLAGS_intel_breadcrumbs.o = $(call cc-disable-warning, uninitialized)
>  CFLAGS_intel_fbdev.o = $(call cc-disable-warning, override-init)
>
>  subdir-ccflags-y += \
> --
> 2.19.1
>


-- 
Thanks,
~Nick Desaulniers
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Nick Desaulniers]

On Thu, Oct 25, 2018 at 12:36 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> This warning is disabled by default in scripts/Makefile.extrawarn when
> W= is not provided but this Makefile adds -Wall after this warning is
> disabled so it shows up in the build when it shouldn't:
>
> In file included from drivers/gpu/drm/i915/intel_breadcrumbs.c:895:
> drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c:350:34: error:
> variable 'wq' is uninitialized when used within its own initialization
> [-Werror,-Wuninitialized]
>         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
>                                         ^~
> ./include/linux/wait.h:74:63: note: expanded from macro
> 'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
>         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
>                                ~~~~                                  ^~~~
> ./include/linux/wait.h:72:33: note: expanded from macro
> '__WAIT_QUEUE_HEAD_INIT_ONSTACK'
>         ({ init_waitqueue_head(&name); name; })
>                                        ^~~~
> 1 error generated.
>
> This warning looks to be a false positive given that init_waitqueue_head
> initializes name before it is used. Rather than disable the warning for
> the full folder like commit 46e2068081e9 ("drm/i915: Disable some extra

cc author/reviewer of 46e2068081e9.

I'm fine with the patch as is, unless others prefer to disable it for
the whole subdir?  We could be playing whack-a-mole in the future
disabling this warning for other translation units.

> clang warnings"), just disable it for the one problematic file because
> it could be a useful warning for other cases.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/220
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
>  drivers/gpu/drm/i915/Makefile | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 1c2857f13ad4..f36c420afb99 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -26,6 +26,7 @@ subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror
>
>  # Fine grained warnings disable
>  CFLAGS_i915_pci.o = $(call cc-disable-warning, override-init)
> +CFLAGS_intel_breadcrumbs.o = $(call cc-disable-warning, uninitialized)
>  CFLAGS_intel_fbdev.o = $(call cc-disable-warning, override-init)
>
>  subdir-ccflags-y += \
> --
> 2.19.1
>


-- 
Thanks,
~Nick Desaulniers

✗ Fi.CI.IGT: failure for drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Patchwork]

== Series Details ==

Series: drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o
URL   : https://patchwork.freedesktop.org/series/51542/
State : failure

== Summary ==

= CI Bug Log - changes from CI_DRM_5037_full -> Patchwork_10585_full =

== Summary - FAILURE ==

  Serious unknown changes coming with Patchwork_10585_full absolutely need to be
  verified manually.
  
  If you think the reported changes have nothing to do with the changes
  introduced in Patchwork_10585_full, please notify your bug team to allow them
  to document this new failure mode, which will reduce false positives in CI.

  

== Possible new issues ==

  Here are the unknown changes that may have been introduced in Patchwork_10585_full:

  === IGT changes ===

    ==== Possible regressions ====

    igt@gem_busy@close-race:
      shard-glk:          PASS -> DMESG-FAIL

    
== Known issues ==

  Here are the changes found in Patchwork_10585_full that come from known issues:

  === IGT changes ===

    ==== Issues hit ====

    igt@drv_suspend@shrink:
      shard-glk:          PASS -> INCOMPLETE (k.org#198133, fdo#106886, fdo#103359)

    igt@gem_exec_schedule@pi-ringfull-blt:
      shard-skl:          NOTRUN -> FAIL (fdo#103158)

    igt@gem_ppgtt@blt-vs-render-ctx0:
      shard-skl:          NOTRUN -> TIMEOUT (fdo#108039) +1

    igt@kms_busy@extended-modeset-hang-newfb-render-a:
      shard-skl:          NOTRUN -> DMESG-WARN (fdo#107956) +2

    igt@kms_busy@extended-modeset-hang-newfb-with-reset-render-c:
      shard-hsw:          PASS -> DMESG-WARN (fdo#107956)

    igt@kms_cursor_crc@cursor-128x128-suspend:
      shard-glk:          PASS -> FAIL (fdo#103232) +1

    igt@kms_cursor_crc@cursor-256x256-random:
      shard-skl:          NOTRUN -> FAIL (fdo#103232)

    igt@kms_cursor_crc@cursor-64x21-random:
      shard-apl:          PASS -> FAIL (fdo#103232) +4

    igt@kms_flip@flip-vs-expired-vblank:
      shard-glk:          PASS -> FAIL (fdo#102887, fdo#105363)

    igt@kms_frontbuffer_tracking@fbc-1p-primscrn-cur-indfb-draw-blt:
      shard-glk:          PASS -> FAIL (fdo#103167) +4

    igt@kms_frontbuffer_tracking@fbc-1p-primscrn-spr-indfb-draw-mmap-gtt:
      shard-apl:          PASS -> FAIL (fdo#103167) +2

    igt@kms_frontbuffer_tracking@fbc-1p-rte:
      shard-glk:          PASS -> FAIL (fdo#103167, fdo#105682)

    igt@kms_frontbuffer_tracking@fbcpsr-1p-primscrn-pri-shrfb-draw-render:
      shard-skl:          NOTRUN -> FAIL (fdo#103167) +3

    igt@kms_plane@plane-position-covered-pipe-a-planes:
      shard-glk:          PASS -> FAIL (fdo#103166) +2

    igt@kms_plane@plane-position-covered-pipe-c-planes:
      shard-apl:          PASS -> DMESG-WARN (fdo#108549) +26

    igt@kms_plane_alpha_blend@pipe-b-coverage-7efc:
      shard-skl:          NOTRUN -> FAIL (fdo#108146)

    igt@kms_plane_alpha_blend@pipe-c-alpha-opaque-fb:
      shard-skl:          NOTRUN -> FAIL (fdo#108145) +1

    igt@kms_plane_alpha_blend@pipe-c-constant-alpha-max:
      shard-glk:          PASS -> FAIL (fdo#108145)

    igt@kms_plane_multiple@atomic-pipe-a-tiling-yf:
      shard-skl:          NOTRUN -> FAIL (fdo#107815, fdo#103166)

    igt@kms_plane_multiple@atomic-pipe-c-tiling-yf:
      shard-apl:          PASS -> FAIL (fdo#103166) +3

    igt@kms_setmode@basic:
      shard-apl:          PASS -> FAIL (fdo#99912)
      shard-skl:          NOTRUN -> FAIL (fdo#99912)

    igt@kms_vblank@pipe-b-ts-continuation-modeset-rpm:
      shard-apl:          PASS -> DMESG-FAIL (fdo#108549) +1

    
    ==== Possible fixes ====

    igt@kms_atomic_transition@1x-modeset-transitions-nonblocking-fencing:
      shard-apl:          DMESG-FAIL (fdo#108549) -> PASS +3

    igt@kms_atomic_transition@plane-all-modeset-transition:
      shard-apl:          INCOMPLETE (fdo#103927) -> PASS

    igt@kms_available_modes_crc@available_mode_test_crc:
      shard-apl:          FAIL (fdo#106641) -> PASS

    igt@kms_busy@extended-pageflip-modeset-hang-oldfb-render-a:
      shard-kbl:          DMESG-WARN (fdo#107956) -> PASS

    igt@kms_ccs@pipe-a-crc-sprite-planes-basic:
      shard-glk:          FAIL (fdo#108145) -> PASS +1

    igt@kms_color@pipe-b-ctm-blue-to-red:
      shard-apl:          DMESG-WARN (fdo#108549) -> PASS +21

    igt@kms_color@pipe-c-degamma:
      shard-apl:          FAIL (fdo#104782) -> PASS

    igt@kms_cursor_crc@cursor-128x42-onscreen:
      shard-apl:          FAIL (fdo#103232) -> PASS +3

    igt@kms_frontbuffer_tracking@fbc-2p-primscrn-cur-indfb-draw-blt:
      shard-glk:          FAIL (fdo#103167) -> PASS +5

    igt@kms_frontbuffer_tracking@fbc-badstride:
      shard-skl:          FAIL (fdo#105682) -> PASS

    igt@kms_frontbuffer_tracking@fbcpsr-1p-primscrn-indfb-msflip-blt:
      shard-skl:          FAIL (fdo#103167) -> PASS +1

    igt@kms_plane@plane-panning-bottom-right-suspend-pipe-a-planes:
      shard-skl:          FAIL (fdo#103166) -> PASS

    igt@kms_plane_multiple@atomic-pipe-c-tiling-x:
      shard-apl:          FAIL (fdo#103166) -> PASS

    igt@kms_plane_multiple@atomic-pipe-c-tiling-y:
      shard-glk:          FAIL (fdo#103166) -> PASS

    igt@pm_rpm@basic-pci-d3-state:
      shard-skl:          INCOMPLETE (fdo#107807) -> PASS

    
  fdo#102887 https://bugs.freedesktop.org/show_bug.cgi?id=102887
  fdo#103158 https://bugs.freedesktop.org/show_bug.cgi?id=103158
  fdo#103166 https://bugs.freedesktop.org/show_bug.cgi?id=103166
  fdo#103167 https://bugs.freedesktop.org/show_bug.cgi?id=103167
  fdo#103232 https://bugs.freedesktop.org/show_bug.cgi?id=103232
  fdo#103359 https://bugs.freedesktop.org/show_bug.cgi?id=103359
  fdo#103927 https://bugs.freedesktop.org/show_bug.cgi?id=103927
  fdo#104782 https://bugs.freedesktop.org/show_bug.cgi?id=104782
  fdo#105363 https://bugs.freedesktop.org/show_bug.cgi?id=105363
  fdo#105682 https://bugs.freedesktop.org/show_bug.cgi?id=105682
  fdo#106641 https://bugs.freedesktop.org/show_bug.cgi?id=106641
  fdo#106886 https://bugs.freedesktop.org/show_bug.cgi?id=106886
  fdo#107807 https://bugs.freedesktop.org/show_bug.cgi?id=107807
  fdo#107815 https://bugs.freedesktop.org/show_bug.cgi?id=107815
  fdo#107956 https://bugs.freedesktop.org/show_bug.cgi?id=107956
  fdo#108039 https://bugs.freedesktop.org/show_bug.cgi?id=108039
  fdo#108145 https://bugs.freedesktop.org/show_bug.cgi?id=108145
  fdo#108146 https://bugs.freedesktop.org/show_bug.cgi?id=108146
  fdo#108549 https://bugs.freedesktop.org/show_bug.cgi?id=108549
  fdo#99912 https://bugs.freedesktop.org/show_bug.cgi?id=99912
  k.org#198133 https://bugzilla.kernel.org/show_bug.cgi?id=198133


== Participating hosts (6 -> 6) ==

  No changes in participating hosts


== Build changes ==

    * Linux: CI_DRM_5037 -> Patchwork_10585

  CI_DRM_5037: e11750586cb6054bd319ad217cecd045febaacc5 @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_4694: ff8d1156723f235e82cb4fcfd2cd6e5a5bb211fa @ git://anongit.freedesktop.org/xorg/app/intel-gpu-tools
  Patchwork_10585: af9ae53ac686bf661bdc630f0aee4364a7a2f1c1 @ git://anongit.freedesktop.org/gfx-ci/linux
  piglit_4509: fdc5a4ca11124ab8413c7988896eec4c97336694 @ git://anongit.freedesktop.org/piglit

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_10585/shards.html
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Nathan Chancellor]

On Thu, Oct 25, 2018 at 12:36:01PM -0700, Nathan Chancellor wrote:
> This warning is disabled by default in scripts/Makefile.extrawarn when
> W= is not provided but this Makefile adds -Wall after this warning is
> disabled so it shows up in the build when it shouldn't:
> 
> In file included from drivers/gpu/drm/i915/intel_breadcrumbs.c:895:
> drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c:350:34: error:
> variable 'wq' is uninitialized when used within its own initialization
> [-Werror,-Wuninitialized]
>         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
>                                         ^~
> ./include/linux/wait.h:74:63: note: expanded from macro
> 'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
>         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
>                                ~~~~                                  ^~~~
> ./include/linux/wait.h:72:33: note: expanded from macro
> '__WAIT_QUEUE_HEAD_INIT_ONSTACK'
>         ({ init_waitqueue_head(&name); name; })
>                                        ^~~~
> 1 error generated.
> 
> This warning looks to be a false positive given that init_waitqueue_head
> initializes name before it is used. Rather than disable the warning for
> the full folder like commit 46e2068081e9 ("drm/i915: Disable some extra
> clang warnings"), just disable it for the one problematic file because
> it could be a useful warning for other cases.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/220
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
>  drivers/gpu/drm/i915/Makefile | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 1c2857f13ad4..f36c420afb99 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -26,6 +26,7 @@ subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror
>  
>  # Fine grained warnings disable
>  CFLAGS_i915_pci.o = $(call cc-disable-warning, override-init)
> +CFLAGS_intel_breadcrumbs.o = $(call cc-disable-warning, uninitialized)
>  CFLAGS_intel_fbdev.o = $(call cc-disable-warning, override-init)
>  
>  subdir-ccflags-y += \
> -- 
> 2.19.1
> 

Gentle ping for review.

Nathan
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Nathan Chancellor]

On Thu, Oct 25, 2018 at 12:36:01PM -0700, Nathan Chancellor wrote:
> This warning is disabled by default in scripts/Makefile.extrawarn when
> W= is not provided but this Makefile adds -Wall after this warning is
> disabled so it shows up in the build when it shouldn't:
> 
> In file included from drivers/gpu/drm/i915/intel_breadcrumbs.c:895:
> drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c:350:34: error:
> variable 'wq' is uninitialized when used within its own initialization
> [-Werror,-Wuninitialized]
>         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
>                                         ^~
> ./include/linux/wait.h:74:63: note: expanded from macro
> 'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
>         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
>                                ~~~~                                  ^~~~
> ./include/linux/wait.h:72:33: note: expanded from macro
> '__WAIT_QUEUE_HEAD_INIT_ONSTACK'
>         ({ init_waitqueue_head(&name); name; })
>                                        ^~~~
> 1 error generated.
> 
> This warning looks to be a false positive given that init_waitqueue_head
> initializes name before it is used. Rather than disable the warning for
> the full folder like commit 46e2068081e9 ("drm/i915: Disable some extra
> clang warnings"), just disable it for the one problematic file because
> it could be a useful warning for other cases.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/220
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
>  drivers/gpu/drm/i915/Makefile | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 1c2857f13ad4..f36c420afb99 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -26,6 +26,7 @@ subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror
>  
>  # Fine grained warnings disable
>  CFLAGS_i915_pci.o = $(call cc-disable-warning, override-init)
> +CFLAGS_intel_breadcrumbs.o = $(call cc-disable-warning, uninitialized)
>  CFLAGS_intel_fbdev.o = $(call cc-disable-warning, override-init)
>  
>  subdir-ccflags-y += \
> -- 
> 2.19.1
> 

Gentle ping for review.

Nathan

Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Chris Wilson]

Quoting Nick Desaulniers (2018-10-25 23:20:58)
> On Thu, Oct 25, 2018 at 12:36 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > This warning is disabled by default in scripts/Makefile.extrawarn when
> > W= is not provided but this Makefile adds -Wall after this warning is
> > disabled so it shows up in the build when it shouldn't:
> >
> > In file included from drivers/gpu/drm/i915/intel_breadcrumbs.c:895:
> > drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c:350:34: error:
> > variable 'wq' is uninitialized when used within its own initialization
> > [-Werror,-Wuninitialized]
> >         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
> >                                         ^~
> > ./include/linux/wait.h:74:63: note: expanded from macro
> > 'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
> >         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
> >                                ~~~~                                  ^~~~
> > ./include/linux/wait.h:72:33: note: expanded from macro
> > '__WAIT_QUEUE_HEAD_INIT_ONSTACK'
> >         ({ init_waitqueue_head(&name); name; })
> >                                        ^~~~
> > 1 error generated.
> >
> > This warning looks to be a false positive given that init_waitqueue_head
> > initializes name before it is used. Rather than disable the warning for
> > the full folder like commit 46e2068081e9 ("drm/i915: Disable some extra
> 
> cc author/reviewer of 46e2068081e9.
> 
> I'm fine with the patch as is, unless others prefer to disable it for
> the whole subdir?  We could be playing whack-a-mole in the future
> disabling this warning for other translation units.

Yes, exactly this since the warning is generated by a core header and a
fairly common pattern its use is not restricted to any single file.
(Will not all selftests similarly explode?)

The other false-positive clang-6 gave was for local_clock_us().
Presumably that one is fixed?
-Chris

Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Nathan Chancellor]

On Tue, Dec 18, 2018 at 11:53:06AM +0000, Chris Wilson wrote:
> Quoting Nick Desaulniers (2018-10-25 23:20:58)
> > On Thu, Oct 25, 2018 at 12:36 PM Nathan Chancellor
> > <natechancellor@gmail.com> wrote:
> > >
> > > This warning is disabled by default in scripts/Makefile.extrawarn when
> > > W= is not provided but this Makefile adds -Wall after this warning is
> > > disabled so it shows up in the build when it shouldn't:
> > >
> > > In file included from drivers/gpu/drm/i915/intel_breadcrumbs.c:895:
> > > drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c:350:34: error:
> > > variable 'wq' is uninitialized when used within its own initialization
> > > [-Werror,-Wuninitialized]
> > >         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
> > >                                         ^~
> > > ./include/linux/wait.h:74:63: note: expanded from macro
> > > 'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
> > >         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
> > >                                ~~~~                                  ^~~~
> > > ./include/linux/wait.h:72:33: note: expanded from macro
> > > '__WAIT_QUEUE_HEAD_INIT_ONSTACK'
> > >         ({ init_waitqueue_head(&name); name; })
> > >                                        ^~~~
> > > 1 error generated.
> > >
> > > This warning looks to be a false positive given that init_waitqueue_head
> > > initializes name before it is used. Rather than disable the warning for
> > > the full folder like commit 46e2068081e9 ("drm/i915: Disable some extra
> > 
> > cc author/reviewer of 46e2068081e9.
> > 
> > I'm fine with the patch as is, unless others prefer to disable it for
> > the whole subdir?  We could be playing whack-a-mole in the future
> > disabling this warning for other translation units.
> 

Hi Chris,

> Yes, exactly this since the warning is generated by a core header and a
> fairly common pattern its use is not restricted to any single file.
> (Will not all selftests similarly explode?)
> 

Well, -Wuninitialized is turned off for the whole kernel unless W= is
passed. So I suppose it should be turned back on for the whole folder
but I noticed that the i915 Makefile purposefully turns all of the
disabled warnings back on for heavier coverage so it makes some sense to
just leave it off for one translation unit when it's just one
translation unit that has the problem. That said, I'm more than happy to
send a v2 turning it off for the whole folder if you think that best.

> The other false-positive clang-6 gave was for local_clock_us().
> Presumably that one is fixed?
> -Chris

With this patch, I can build i915 using defconfig and allyesconfig
without any warnings with tip-of-tree Clang.

Thank you for the comments!
Nathan
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Nathan Chancellor]

On Tue, Dec 18, 2018 at 11:53:06AM +0000, Chris Wilson wrote:
> Quoting Nick Desaulniers (2018-10-25 23:20:58)
> > On Thu, Oct 25, 2018 at 12:36 PM Nathan Chancellor
> > <natechancellor@gmail.com> wrote:
> > >
> > > This warning is disabled by default in scripts/Makefile.extrawarn when
> > > W= is not provided but this Makefile adds -Wall after this warning is
> > > disabled so it shows up in the build when it shouldn't:
> > >
> > > In file included from drivers/gpu/drm/i915/intel_breadcrumbs.c:895:
> > > drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c:350:34: error:
> > > variable 'wq' is uninitialized when used within its own initialization
> > > [-Werror,-Wuninitialized]
> > >         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
> > >                                         ^~
> > > ./include/linux/wait.h:74:63: note: expanded from macro
> > > 'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
> > >         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
> > >                                ~~~~                                  ^~~~
> > > ./include/linux/wait.h:72:33: note: expanded from macro
> > > '__WAIT_QUEUE_HEAD_INIT_ONSTACK'
> > >         ({ init_waitqueue_head(&name); name; })
> > >                                        ^~~~
> > > 1 error generated.
> > >
> > > This warning looks to be a false positive given that init_waitqueue_head
> > > initializes name before it is used. Rather than disable the warning for
> > > the full folder like commit 46e2068081e9 ("drm/i915: Disable some extra
> > 
> > cc author/reviewer of 46e2068081e9.
> > 
> > I'm fine with the patch as is, unless others prefer to disable it for
> > the whole subdir?  We could be playing whack-a-mole in the future
> > disabling this warning for other translation units.
> 

Hi Chris,

> Yes, exactly this since the warning is generated by a core header and a
> fairly common pattern its use is not restricted to any single file.
> (Will not all selftests similarly explode?)
> 

Well, -Wuninitialized is turned off for the whole kernel unless W= is
passed. So I suppose it should be turned back on for the whole folder
but I noticed that the i915 Makefile purposefully turns all of the
disabled warnings back on for heavier coverage so it makes some sense to
just leave it off for one translation unit when it's just one
translation unit that has the problem. That said, I'm more than happy to
send a v2 turning it off for the whole folder if you think that best.

> The other false-positive clang-6 gave was for local_clock_us().
> Presumably that one is fixed?
> -Chris

With this patch, I can build i915 using defconfig and allyesconfig
without any warnings with tip-of-tree Clang.

Thank you for the comments!
Nathan

Re: [PATCH] drm/i915: Disable -Wuninitialized for intel_breadcrumbs.o

[Nick Desaulniers]

On Tue, Dec 18, 2018 at 11:01 AM Nathan Chancellor
<natechancellor@gmail.com> wrote:
> On Tue, Dec 18, 2018 at 11:53:06AM +0000, Chris Wilson wrote:
> > The other false-positive clang-6 gave was for local_clock_us().
> > Presumably that one is fixed?
>
> With this patch, I can build i915 using defconfig and allyesconfig
> without any warnings with tip-of-tree Clang.

Also, please let us know about any other bugs found via testing with
Clang: https://github.com/ClangBuiltLinux/linux/issues

We're happy to take a look!
-- 
Thanks,
~Nick Desaulniers