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From:   "GONG, Ruiqi" <gongruiqi@huaweicloud.com>
To:     Harry Wentland <harry.wentland@amd.com>,
        Leo Li <sunpeng.li@amd.com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        Pan Xinhui <Xinhui.Pan@amd.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>
Cc:     amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org,
        Wang Weiyang <wangweiyang2@huawei.com>,
        Xiu Jianfeng <xiujianfeng@huawei.com>, gongruiqi1@huawei.com
Subject: [PATCH] drm/amd/display: fix compilation error due to shifting negative value
Date:   Fri,  2 Jun 2023 18:12:33 +0800
Message-Id: <20230602101233.1255276-1-gongruiqi@huaweicloud.com>
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Precedence: bulk

Currently compiling linux-next with allmodconfig triggers the following
error:

./drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h: In function ‘dc_fixpt_truncate’:
./drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:528:22: error: left shift of negative value [-Werror=shift-negative-value]
  528 |  arg.value &= (~0LL) << (FIXED31_32_BITS_PER_FRACTIONAL_PART - frac_bits);
      |                      ^~

Use `unsigned long long` instead.

Signed-off-by: GONG, Ruiqi <gongruiqi@huaweicloud.com>
---
 drivers/gpu/drm/amd/display/include/fixed31_32.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/include/fixed31_32.h b/drivers/gpu/drm/amd/display/include/fixed31_32.h
index ece97ae0e826..d4cf7ead1d87 100644
--- a/drivers/gpu/drm/amd/display/include/fixed31_32.h
+++ b/drivers/gpu/drm/amd/display/include/fixed31_32.h
@@ -525,7 +525,7 @@ static inline struct fixed31_32 dc_fixpt_truncate(struct fixed31_32 arg, unsigne
 
 	if (negative)
 		arg.value = -arg.value;
-	arg.value &= (~0LL) << (FIXED31_32_BITS_PER_FRACTIONAL_PART - frac_bits);
+	arg.value &= (~0ULL) << (FIXED31_32_BITS_PER_FRACTIONAL_PART - frac_bits);
 	if (negative)
 		arg.value = -arg.value;
 	return arg;
-- 
2.25.1