From: Arnd Bergmann <arnd@arndb.de>
To: "Alex Deucher" <alexander.deucher@amd.com>,
"Christian König" <christian.koenig@amd.com>
Cc: Arnd Bergmann <arnd@arndb.de>, David Airlie <airlied@linux.ie>,
Harry Wentland <harry.wentland@amd.com>,
Tony Cheng <tony.cheng@amd.com>,
Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>,
Joshua Aberback <Joshua.Aberback@amd.com>,
"Leo (Sunpeng) Li" <sunpeng.li@amd.com>,
amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 3/3] drm/amdgpu/display: fix integer arithmetic problem
Date: Thu, 2 Nov 2017 12:26:43 +0100 [thread overview]
Message-ID: <20171102112657.111405-3-arnd@arndb.de> (raw)
In-Reply-To: <20171102112657.111405-1-arnd@arndb.de>
gcc warns about an ambiguous integer calculation:
drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dce_calcs.c: In function 'calculate_bandwidth':
drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dce_calcs.c:534:5: error: this decimal constant is unsigned only in ISO C90 [-Werror]
data->lb_line_pitch = bw_ceil2(bw_mul(bw_div(bw_frc_to_fixed(2401171875, 100000000), bw_int_to_fixed(3)), bw_ceil2(data->source_width_in_lb, bw_int_to_fixed(8))), bw_int_to_fixed(48));
^~~~
Marking the constant as explicitly unsigned makes it work fine everywhere
without warnings.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
index 15cbfc400633..4f8a95368ffc 100644
--- a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
+++ b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
@@ -531,7 +531,7 @@ static void calculate_bandwidth(
}
switch (data->lb_bpc[i]) {
case 8:
- data->lb_line_pitch = bw_ceil2(bw_mul(bw_div(bw_frc_to_fixed(2401171875, 100000000), bw_int_to_fixed(3)), bw_ceil2(data->source_width_in_lb, bw_int_to_fixed(8))), bw_int_to_fixed(48));
+ data->lb_line_pitch = bw_ceil2(bw_mul(bw_div(bw_frc_to_fixed(2401171875ul, 100000000), bw_int_to_fixed(3)), bw_ceil2(data->source_width_in_lb, bw_int_to_fixed(8))), bw_int_to_fixed(48));
break;
case 10:
data->lb_line_pitch = bw_ceil2(bw_mul(bw_div(bw_frc_to_fixed(300234375, 10000000), bw_int_to_fixed(3)), bw_ceil2(data->source_width_in_lb, bw_int_to_fixed(8))), bw_int_to_fixed(48));
--
2.9.0
next prev parent reply other threads:[~2017-11-02 11:27 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-02 11:26 [PATCH 1/3] drm/amdgpu/display: provide ASSERT macros unconditionally Arnd Bergmann
2017-11-02 11:26 ` [PATCH 2/3] drm/amdgpu/display: remove unused REG_OFFSET macro Arnd Bergmann
2017-11-02 11:26 ` Arnd Bergmann [this message]
2017-11-02 14:02 ` [PATCH 3/3] drm/amdgpu/display: fix integer arithmetic problem Harry Wentland
2017-11-02 14:09 ` [PATCH 1/3] drm/amdgpu/display: provide ASSERT macros unconditionally Felix Kuehling
2017-11-02 14:20 ` Arnd Bergmann
2017-11-02 14:26 ` Alex Deucher
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