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drm/amdgpu/display: fix integer arithmetic problem
authorArnd Bergmann <arnd@arndb.de>
Thu, 2 Nov 2017 11:26:43 +0000 (12:26 +0100)
committerAlex Deucher <alexander.deucher@amd.com>
Thu, 2 Nov 2017 17:44:41 +0000 (13:44 -0400)
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(2401171875100000000), 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.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c

index 15cbfc4..4f8a953 100644 (file)
@@ -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));