suspicious conditions in amd display driver

[Denis Efremov]

Hi,

I've found suspicious code patterns in amd display driver.
For me they looks like redundant comparisons, but maybe it's logic bugs
and dm_444_16, dm_whole_buffer_for_single_stream_interleave should be changed to
other variables in second disjuncts.

Here are they:

diff -u -p ./drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c 
/tmp/nothing/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c
--- ./drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c
+++ /tmp/nothing/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c
@@ -3235,7 +3235,6 @@ static bool CalculateBytePerPixelAnd256B
                *BytePerPixelDETC = 0;
                *BytePerPixelY = 4;
                *BytePerPixelC = 0;
-       } else if (SourcePixelFormat == dm_444_16 || SourcePixelFormat == 
dm_444_16) { // <== same comparison with dm_444_16
                *BytePerPixelDETY = 2;
                *BytePerPixelDETC = 0;
        *BytePerPixelY = 2;

@@ -5515,7 +5514,6 @@ static void CalculateWatermarksAndDRAMSp
        if (WritebackPixelFormat[k] == dm_444_64) {
                WritebackDRAMClockChangeLatencyHiding = 
WritebackDRAMClockChangeLatencyHiding / 2;
        }
-       if (mode_lib->vba.WritebackConfiguration == 
dm_whole_buffer_for_single_stream_interleave || 
mode_lib->vba.WritebackConfiguration == 
dm_whole_buffer_for_single_stream_interleave) { // <== same comparison with 
dm_whole_buffer_for_single_stream_interleave


diff -u -p ./drivers/gpu/drm/amd/display/dc/dml/dcn30/display_rq_dlg_calc_30.c 
/tmp/nothing/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_rq_dlg_calc_30.c
--- ./drivers/gpu/drm/amd/display/dc/dml/dcn30/display_rq_dlg_calc_30.c
+++ 
/tmp/nothing/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_rq_dlg_calc_30.c
@@ -279,7 +279,6 @@ static bool CalculateBytePerPixelAnd256B
                *BytePerPixelDETC = 0;
                *BytePerPixelY = 4;
                *BytePerPixelC = 0;
-       } else if (SourcePixelFormat == dm_444_16 || SourcePixelFormat == 
dm_444_16) { // <== same comparison with dm_444_16
                *BytePerPixelDETY = 2;
                *BytePerPixelDETC = 0;
                *BytePerPixelY = 2;

Thanks,
Denis
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx