glmark2 performance drops when screen is rotated to 90/270

[vishnumotghare-eaton]

I have an IMX.6 custom board running on the yocto Kirkstone version. Following is my configuration

Linux:            Mainline 5.15
GPU driver:       Etnaviv
X Driver:         xf86-video-modesetting

=======================================================
    glmark2 2021.12
=======================================================
    OpenGL Information
    GL_VENDOR:     Mesa
    GL_RENDERER:   Vivante GC880 rev 5106
    GL_VERSION:    OpenGL ES 2.0 Mesa 23.3.3

When I run glmark2 in normal mode, I get a score of 64

[build] use-vbo=false: FPS: 112 FrameTime: 8.929 ms
[build] use-vbo=true: FPS: 122 FrameTime: 8.197 ms
[texture] texture-filter=nearest: FPS: 99 FrameTime: 10.101 ms
[texture] texture-filter=linear: FPS: 98 FrameTime: 10.204 ms
[texture] texture-filter=mipmap: FPS: 95 FrameTime: 10.526 ms
[shading] shading=gouraud: FPS: 106 FrameTime: 9.434 ms
[shading] shading=blinn-phong-inf: FPS: 85 FrameTime: 11.765 ms
[shading] shading=phong: FPS: 67 FrameTime: 14.925 ms
[shading] shading=cel: FPS: 54 FrameTime: 18.519 ms
[bump] bump-render=high-poly: FPS: 71 FrameTime: 14.085 ms
[bump] bump-render=normals: FPS: 99 FrameTime: 10.101 ms
[bump] bump-render=height: FPS: 88 FrameTime: 11.364 ms
[effect2d] kernel=0,1,0;1,-4,1;0,1,0;: FPS: 51 FrameTime: 19.608 ms
<skip>

 FPS: 4 FrameTime: 250.000 ms
[shadow] <default>: FPS: 31 FrameTime: 32.258 ms
[refract] <default>: FPS: 8 FrameTime: 125.000 ms
[conditionals] fragment-steps=0:vertex-steps=0: FPS: 99 FrameTime: 10.101 ms
[conditionals] fragment-steps=5:vertex-steps=0: FPS: 49 FrameTime: 20.408 ms
[conditionals] fragment-steps=0:vertex-steps=5: FPS: 96 FrameTime: 10.417 ms
[function] fragment-complexity=low:fragment-steps=5: FPS: 66 FrameTime: 15.152 ms
[function] fragment-complexity=medium:fragment-steps=5: FPS: 44 FrameTime: 22.727 ms
[loop] fragment-loop=false:fragment-steps=5:vertex-steps=5: FPS: 64 FrameTime: 15.625 ms
[loop] fragment-steps=5:fragment-uniform=false:vertex-steps=5: FPS: 64 FrameTime: 15.625 ms
[loop] fragment-steps=5:fragment-uniform=true:vertex-steps=5: FPS: 35 FrameTime: 28.571 ms
=======================================================
                                  glmark2 Score: 65
=======================================================

When I run glmark2 when the screen is rotated to 90/270, I get a score of 16. Why is performance dropped when the screen is rotated?

[build] use-vbo=false: FPS: 23 FrameTime: 43.478 ms
[build] use-vbo=true: FPS: 23 FrameTime: 43.478 ms
[texture] texture-filter=nearest: FPS: 21 FrameTime: 47.619 ms
[texture] texture-filter=linear: FPS: 21 FrameTime: 47.619 ms
[texture] texture-filter=mipmap: FPS: 21 FrameTime: 47.619 ms
[shading] shading=gouraud: FPS: 22 FrameTime: 45.455 ms
[shading] shading=blinn-phong-inf: FPS: 19 FrameTime: 52.632 ms
[shading] shading=phong: FPS: 17 FrameTime: 58.824 ms
[shading] shading=cel: FPS: 15 FrameTime: 66.667 ms
[bump] bump-render=high-poly: FPS: 18 FrameTime: 55.556 ms
[bump] bump-render=normals: FPS: 20 FrameTime: 50.000 ms
[bump] bump-render=height: FPS: 19 FrameTime: 52.632 ms
[effect2d] kernel=0,1,0;1,-4,1;0,1,0;: FPS: 17 FrameTime: 58.824 ms
[effect2d] kernel=1,1,1,1,1;1,1,1,1,1;1,1,1,1,1;: FPS: 11 FrameTime: 90.909 ms
[pulsar] light=false:quads=5:texture=false: FPS: 20 FrameTime: 50.000 ms
[desktop] blur-radius=5:effect=blur:passes=1:separable=true:windows=4: FPS: 11 FrameTime: 90.909 ms
[desktop] effect=shadow:windows=4: FPS: 18 FrameTime: 55.556 ms
[buffer] columns=200:interleave=false:update-dispersion=0.9:update-fraction=0.5:update-method=map: FPS: 19 FrameTime: 52.632 ms
[buffer] columns=200:interleave=false:update-dispersion=0.9:update-fraction=0.5:update-method=subdata: FPS: 18 FrameTime: 55.556 ms
[buffer] columns=200:interleave=true:update-dispersion=0.9:update-fraction=0.5:update-method=map: FPS: 19 FrameTime: 52.632 ms
[ideas] speed=duration: FPS: 19 FrameTime: 52.632 ms
[jellyfish] <default>: FPS: 13 FrameTime: 76.923 ms

<skip>

 FPS: 3 FrameTime: 333.333 ms
[shadow] <default>: FPS: 13 FrameTime: 76.923 ms
[refract] <default>: FPS: 4 FrameTime: 250.000 ms
[conditionals] fragment-steps=0:vertex-steps=0: FPS: 21 FrameTime: 47.619 ms
[conditionals] fragment-steps=5:vertex-steps=0: FPS: 15 FrameTime: 66.667 ms
[conditionals] fragment-steps=0:vertex-steps=5: FPS: 21 FrameTime: 47.619 ms
[function] fragment-complexity=low:fragment-steps=5: FPS: 17 FrameTime: 58.824 ms
[function] fragment-complexity=medium:fragment-steps=5: FPS: 14 FrameTime: 71.429 ms
[loop] fragment-loop=false:fragment-steps=5:vertex-steps=5: FPS: 17 FrameTime: 58.824 ms
[loop] fragment-steps=5:fragment-uniform=false:vertex-steps=5: FPS: 17 FrameTime: 58.824 ms
[loop] fragment-steps=5:fragment-uniform=true:vertex-steps=5: FPS: 12 FrameTime: 83.333 ms
=======================================================
                                  glmark2 Score: 16
=======================================================