<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - [SKL bisected] texsubimage pbo intermittent failures" href="https://bugs.freedesktop.org/show_bug.cgi?id=91926#c72">Comment # 72</a> on <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - [SKL bisected] texsubimage pbo intermittent failures" href="https://bugs.freedesktop.org/show_bug.cgi?id=91926">bug 91926</a> from <a class="email" href="mailto:topi.pohjolainen@intel.com" title="Topi Pohjolainen <topi.pohjolainen@intel.com>"> Topi Pohjolainen</a> <pre>The final blit from the texture to the framebuffer is executed using fixed-function fragment shader. I hacked Mesa to simulate the color values in the test for R-component - the test uses values depending on the Y-component, specifically R = 4 * y. So I hacked Mesa to overwrite the R-component to 4 * y instead of using the value read from the texture: pln(8) g127<1>F g5.4<0,1,0>F g2<8,8,1>F pln(8) g8<1>F g6<0,1,0>F g2<8,8,1>F pln(8) g9<1>F g6.4<0,1,0>F g2<8,8,1>F pln(8) g4<1>F g7.4<0,1,0>F g2<8,8,1>F mul(8) g124<1>F g9<8,8,1>F 4F math inv(8) g5<1>F g4<8,8,1>F null mul(8) g2<1>F g8<8,8,1>F g5<8,8,1>F mul(8) g3<1>F g9<8,8,1>F g5<8,8,1>F send(8) g2<1>UW g2<8,8,1>F sampler sample SIMD8 Surface = 1 Sampler = 0 mlen 2 rlen 4 { align1 1Q }; mov(8) g125<1>F g3<8,8,1>F mov(8) g126<1>F g4<8,8,1>F sendc(8) null g124<8,8,1>F render RT write SIMD8 LastRT Surface = 0 mlen 4 rlen 0 { align1 1Q EOT }; With this I can get the same intermittent pixel failures I'm seeing without: 32:0:0:255 0:0:0:255 x=0 y=8 z=0 32:2:0:255 0:2:0:255 x=1 y=8 z=0 32:4:0:255 0:4:0:255 x=2 y=8 z=0 32:6:0:255 0:6:0:255 x=3 y=8 z=0 36:0:0:255 4:0:0:255 x=0 y=9 z=0 36:2:0:255 4:2:0:255 x=1 y=9 z=0 36:4:0:255 4:4:0:255 x=2 y=9 z=0 36:6:0:255 4:6:0:255 x=3 y=9 z=0 40:0:0:255 8:0:0:255 x=0 y=10 z=0 40:2:0:255 8:2:0:255 x=1 y=10 z=0 40:4:0:255 8:4:0:255 x=2 y=10 z=0 40:6:0:255 8:6:0:255 x=3 y=10 z=0 44:0:0:255 12:0:0:255 x=0 y=11 z=0 44:2:0:255 12:2:0:255 x=1 y=11 z=0 44:4:0:255 12:4:0:255 x=2 y=11 z=0 44:6:0:255 12:6:0:255 x=3 y=11 z=0 First four values are the expected, second four are the values read back. This tells us that the problem isn't necessarily sampling - it looks that the y-coordinate is being wrong during the tex-2-fb blit.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>