System Environment:
--------------------------

--Platform: G965

--Architecture(32-bit,64-bit,compatiblity): all

--2D driver(2.4 branch):  45c1da56891723dd85153853885dd3b52a23c117

--mesa(7_0 branch): 2c9e332bceb85435aa5e4ad4d43fc97c7272bf98

--Xserver(1.4 branch): c3a7903f6a6a27e53ba0372408e0c5a68c608e86

--LibDrm: 2.3.0

--Kernel:
2.6.23.1


Bug detailed description:
-------------------------
this issue happens on G45 with direct rendering.
this issue doesn't happen on G965 with direct rendering.

glean case blendFunc failed with following output:
blendFunc:  PASS rgba8, db, win+pmap, id 35
blendFunc:  PASS rgba8, win+pmap, id 36
blendFunc:  PASS rgba8, db, z24, s8, win+pmap, id 37
blendFunc:  PASS rgba8, z24, s8, win+pmap, id 38
blendFunc:  FAIL rgba8, db, accrgba16, win+pmap, slow, id 39
        source factor RGB = GL_ONE_MINUS_DST_ALPHA, source factor A = GL_ZERO
        dest factor RGB = GL_ONE_MINUS_DST_ALPHA, dest factor A = GL_ZERO
        equation RGB = GL_FUNC_ADD, equation A = GL_FUNC_ADD
        const color = { 0.25, 0, 1, 0.75 }
        Readback had 0 bits in error; blending had 1.87238 bits in error.
blendFunc:  PASS rgba8, accrgba16, win+pmap, slow, id 40
blendFunc:  PASS rgba8, db, z24, s8, accrgba16, win+pmap, slow, id 41
blendFunc:  PASS rgba8, z24, s8, accrgba16, win+pmap, slow, id 42
blendFunc:  FAIL rgba8, db, win+pmap, id 43
        source factor RGB = GL_CONSTANT_COLOR, source factor A = GL_CONSTANT_COL                                             OR
        dest factor RGB = GL_CONSTANT_COLOR, dest factor A = GL_ZERO
        equation RGB = GL_FUNC_ADD, equation A = GL_FUNC_ADD
        const color = { 0.25, 0, 1, 0.75 }
        Readback had 0 bits in error; blending had 5.08246 bits in error.
blendFunc:  PASS rgba8, win+pmap, id 44
blendFunc:  FAIL rgba8, db, z24, s8, win+pmap, id 45
        source factor RGB = GL_ONE_MINUS_CONSTANT_COLOR, source factor A = GL_SRC_ALPHA
        dest factor RGB = GL_SRC_ALPHA, dest factor A = GL_CONSTANT_ALPHA
        equation RGB = GL_FUNC_ADD, equation A = GL_FUNC_ADD
        const color = { 0.25, 0, 1, 0.75 }
        Readback had 0 bits in error; blending had 6.88255 bits in error.
blendFunc:  PASS rgba8, z24, s8, win+pmap, id 46
blendFunc:  PASS rgba8, db, accrgba16, win+pmap, slow, id 47
blendFunc:  PASS rgba8, accrgba16, win+pmap, slow, id 48
blendFunc:  PASS rgba8, db, z24, s8, accrgba16, win+pmap, slow, id 49
blendFunc:  FAIL rgba8, z24, s8, accrgba16, win+pmap, slow, id 50
        source factor RGB = GL_ONE_MINUS_DST_COLOR, source factor A = GL_SRC_ALPHA_SATURATE
        dest factor RGB = GL_ONE, dest factor A = GL_ONE_MINUS_CONSTANT_ALPHA
        equation RGB = GL_FUNC_ADD, equation A = GL_FUNC_ADD
        const color = { 0.25, 0, 1, 0.75 }
        Readback had 4.39796 bits in error; blending had 1.21097 bits in error.
blendFunc:  FAIL rgba8, win+pmap, nonconformant, id 112
        source factor RGB = GL_ONE_MINUS_SRC_ALPHA, source factor A = GL_ONE_MINUS_CONSTANT_ALPHA
        dest factor RGB = GL_ZERO, dest factor A = GL_ONE_MINUS_SRC_COLOR
        equation RGB = GL_FUNC_ADD, equation A = GL_FUNC_ADD
        const color = { 0.25, 0, 1, 0.75 }
        Readback had 7.88216 bits in error; blending had 7.41413 bits in error.



Reproduce steps:
----------------
1. start X
2. glean -r test -t blendFunc

Current result:
----------------
glean case blendFunc failed