From: Harry Wentland Date: Fri, 10 Nov 2017 17:11:44 +0000 (-0500) Subject: drm/amd/display: Fix use before NULL check in validate_timing X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b001965d4eb5e4c0e3de7dc6dce1d45ca25232a7;p=linux.git drm/amd/display: Fix use before NULL check in validate_timing Found by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/dce110/dce110_timing_generator.c:1124 dce110_timing_generator_validate_timing() warn: variable dereferenced before check 'timing' (see line 1116) Signed-off-by: Harry Wentland Reviewed-by: Tony Cheng Acked-by: Harry Wentland Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/display/dc/dce110/dce110_timing_generator.c b/drivers/gpu/drm/amd/display/dc/dce110/dce110_timing_generator.c index 67ac737eaa7e9..4befce6cd87a2 100644 --- a/drivers/gpu/drm/amd/display/dc/dce110/dce110_timing_generator.c +++ b/drivers/gpu/drm/amd/display/dc/dce110/dce110_timing_generator.c @@ -1112,10 +1112,7 @@ bool dce110_timing_generator_validate_timing( enum signal_type signal) { uint32_t h_blank; - uint32_t h_back_porch; - uint32_t hsync_offset = timing->h_border_right + - timing->h_front_porch; - uint32_t h_sync_start = timing->h_addressable + hsync_offset; + uint32_t h_back_porch, hsync_offset, h_sync_start; struct dce110_timing_generator *tg110 = DCE110TG_FROM_TG(tg); @@ -1124,6 +1121,9 @@ bool dce110_timing_generator_validate_timing( if (!timing) return false; + hsync_offset = timing->h_border_right + timing->h_front_porch; + h_sync_start = timing->h_addressable + hsync_offset; + /* Currently we don't support 3D, so block all 3D timings */ if (timing->timing_3d_format != TIMING_3D_FORMAT_NONE) return false;