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References: <20210103135158.3591442-1-arnd@kernel.org>
Subject: Re: [PATCH] [v2] i915: fix shift warning
From:   Chris Wilson <chris@chris-wilson.co.uk>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Tvrtko Ursulin <tvrtko.ursulin@intel.com>,
        Matthew Auld <matthew.auld@intel.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Dave Airlie <airlied@redhat.com>,
        intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
To:     Arnd Bergmann <arnd@kernel.org>, Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>
Date:   Sun, 03 Jan 2021 14:01:59 +0000
Message-ID: <160968251911.30283.15581575287166640028@build.alporthouse.com>
User-Agent: alot/0.9
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Quoting Arnd Bergmann (2021-01-03 13:51:44)
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Randconfig builds on 32-bit machines show lots of warnings for
> the i915 driver for passing a 32-bit value into __const_hweight64():
> 
> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:2584:9: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
>         return hweight64(VDBOX_MASK(&i915->gt));
>                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/asm-generic/bitops/const_hweight.h:29:49: note: expanded from macro 'hweight64'
>  #define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w))
> 
> Change it to hweight_long() to avoid the warning.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by:: Chris Wilson <chris@chris-wilson.co.uk>
-Chris