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<p class="MsoNormal">Hello here are some details about the problem.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">-Operative System: QNX<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">-Symptoms: Aproximately 1 out of 200 video mode switches will cause the CPU to hang during the next 30-60 VSYNC signals after the mode switches.After hang up most motherboards switch power off after 5-10 seconds.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The mode switcher is based on the document Intel OpenSource HD Graphics Programmer’s Reference Manual (PRM) Volume 3 Part 2: Display Registers – CPU Registers (SandyBridge), chapter 1.1.2 for Sandy Bridge<o:p></o:p></p>
<p class="MsoNormal">https://01.org/linuxgraphics/sites/default/files/documentation/snb_ihd_os_vol3_part2.pdf<o:p></o:p></p>
<p class="MsoNormal">Experimentally it has been determined that the problem can occur after switching on the DSPACNTR bit 31.<o:p></o:p></p>
<p class="MsoNormal">The problem is reproducible using any display controller, and any video output. It has been tested in different combinations of SandyBridge and IvyBridge platfors, with different chipsets.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any help would be appreciated.<o:p></o:p></p>
<p class="MsoNormal">Regards,<o:p></o:p></p>
<p class="MsoNormal">Adolfo<o:p></o:p></p>
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