[Intel-gfx] [PATCH] Revert "drm/i915: use localized __diag_ignore_all() instead of per file"

[Gustavo Sousa]

Quoting Jani Nikula (2023-07-11 08:02:14-03:00)
>This reverts commit 88e9664434c994e97a9f6f8cdd1535495c660cea.
>
>__diag_ignore_all() only works for GCC 8 or later.
>
>-Woverride-init (from -Wextra, enabled in i915 Makefile) combined with
>CONFIG_WERROR=y or W=e breaks the build for older GCC.
>
>With i386_defconfig and x86_64_defconfig enabling CONFIG_WERROR=y by
>default, we really need to roll back the change.
>
>An alternative would be to disable -Woverride-init in the Makefile for
>GCC <8, but the revert seems like the safest bet now.

Sounds good. We would keep it compatible with older compilers and still have the
warning enabled on newer environments.

Another alternative I thought about was to have separate files only for
initializations of that type (i.e. that would need the warning disabled), but I
guess we would need to expose a lot of symbols for that to work...

Reviewed-by: Gustavo Sousa <gustavo.sousa at intel.com>

>
>Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8768
>Reported-by: John Garry <john.g.garry at oracle.com>
>References: https://lore.kernel.org/r/ad2601c0-84bb-c574-3702-a83ff8faf98c@oracle.com
>References: https://lore.kernel.org/r/87wmzezns4.fsf@intel.com
>Fixes: 88e9664434c9 ("drm/i915: use localized __diag_ignore_all() instead of per file")
>Cc: Gustavo Sousa <gustavo.sousa at intel.com>
>Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
>Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
>Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>---
> drivers/gpu/drm/i915/Makefile                       | 5 +++++
> drivers/gpu/drm/i915/display/intel_display_device.c | 5 -----
> drivers/gpu/drm/i915/display/intel_fbdev.c          | 5 -----
> drivers/gpu/drm/i915/i915_pci.c                     | 5 -----
> 4 files changed, 5 insertions(+), 15 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
>index 2be9dd960540..c5fc91cd58e7 100644
>--- a/drivers/gpu/drm/i915/Makefile
>+++ b/drivers/gpu/drm/i915/Makefile
>@@ -23,6 +23,11 @@ subdir-ccflags-y += $(call cc-option, -Wunused-but-set-variable)
> subdir-ccflags-y += $(call cc-disable-warning, frame-address)
> subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror
> 
>+# Fine grained warnings disable
>+CFLAGS_i915_pci.o = $(call cc-disable-warning, override-init)
>+CFLAGS_display/intel_display_device.o = $(call cc-disable-warning, override-init)
>+CFLAGS_display/intel_fbdev.o = $(call cc-disable-warning, override-init)
>+
> subdir-ccflags-y += -I$(srctree)/$(src)
> 
> # Please keep these build lists sorted!
>diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
>index e4afa7334c82..8286e79522d1 100644
>--- a/drivers/gpu/drm/i915/display/intel_display_device.c
>+++ b/drivers/gpu/drm/i915/display/intel_display_device.c
>@@ -16,9 +16,6 @@
> #include "intel_display_reg_defs.h"
> #include "intel_fbc.h"
> 
>-__diag_push();
>-__diag_ignore_all("-Woverride-init", "Allow overriding inherited members");
>-
> static const struct intel_display_device_info no_display = {};
> 
> #define PIPE_A_OFFSET                0x70000
>@@ -727,8 +724,6 @@ static const struct intel_display_device_info xe_lpdp_display = {
>                 BIT(PORT_TC1) | BIT(PORT_TC2) | BIT(PORT_TC3) | BIT(PORT_TC4),
> };
> 
>-__diag_pop();
>-
> #undef INTEL_VGA_DEVICE
> #undef INTEL_QUANTA_VGA_DEVICE
> #define INTEL_VGA_DEVICE(id, info) { id, info }
>diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
>index 1cc0ddc6a310..80c3f88310db 100644
>--- a/drivers/gpu/drm/i915/display/intel_fbdev.c
>+++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
>@@ -135,9 +135,6 @@ static int intel_fbdev_mmap(struct fb_info *info, struct vm_area_struct *vma)
>         return i915_gem_fb_mmap(obj, vma);
> }
> 
>-__diag_push();
>-__diag_ignore_all("-Woverride-init", "Allow overriding the default ops");
>-
> static const struct fb_ops intelfb_ops = {
>         .owner = THIS_MODULE,
>         __FB_DEFAULT_DEFERRED_OPS_RDWR(intel_fbdev),
>@@ -149,8 +146,6 @@ static const struct fb_ops intelfb_ops = {
>         .fb_mmap = intel_fbdev_mmap,
> };
> 
>-__diag_pop();
>-
> static int intelfb_alloc(struct drm_fb_helper *helper,
>                          struct drm_fb_helper_surface_size *sizes)
> {
>diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
>index dea3609fc496..fcacdc21643c 100644
>--- a/drivers/gpu/drm/i915/i915_pci.c
>+++ b/drivers/gpu/drm/i915/i915_pci.c
>@@ -38,9 +38,6 @@
> #include "i915_reg.h"
> #include "intel_pci_config.h"
> 
>-__diag_push();
>-__diag_ignore_all("-Woverride-init", "Allow overriding inherited members");
>-
> #define PLATFORM(x) .platform = (x)
> #define GEN(x) \
>         .__runtime.graphics.ip.ver = (x), \
>@@ -846,8 +843,6 @@ static const struct intel_device_info mtl_info = {
> 
> #undef PLATFORM
> 
>-__diag_pop();
>-
> /*
>  * Make sure any device matches here are from most specific to most
>  * general.  For example, since the Quanta match is based on the subsystem
>-- 
>2.39.2
>