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<p class="MsoNormal">Hi all,<o:p></o:p></p>
<p class="MsoPlainText"> I'm interesting in how mesa/kernel control cache ability of render cache.<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"> My question is based on SKL platform with console (no-X) environment. We can take kmscube(<a href="https://github.com/robclark/kmscube.git">https://github.com/robclark/kmscube.git</a>)
<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in">as an example, it use mesa do rendering and use drm to show result on screen:<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"> gbm_surface_create to create gbm_surface<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"> eglCreateWindowSurface to create EGLSurface<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"> eglMakeCurrent to bind context to EGLSurface<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"> do rendering using glsl<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"> eglSwapBuffers<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"> drmModePageFlip to do page flip<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText" style="text-indent:.5in">As far as I know, display engine always read memory (not cache) of scanout buffer directly. But mesa use Render Cache Data Port
<o:p></o:p></p>
<p class="MsoPlainText" style="text-indent:.5in">to render to framebuffer, so the cache path is: Render Cache -> LLC -> Memory. So what does mesa/kernel do to make render cache
<o:p></o:p></p>
<p class="MsoPlainText" style="text-indent:.5in">coherent with Memory? (I have already seen that cache ability of LLC is set to UC in MOCS of renderbufer. How about render cache?)<o:p></o:p></p>
<p class="MsoPlainText" style="text-indent:.5in">Also set render cache to UC? Or just flush render cache before display?<o:p></o:p></p>
<p class="MsoPlainText" style="text-indent:.5in"><o:p> </o:p></p>
<p class="MsoPlainText" style="text-indent:.5in"><o:p> </o:p></p>
<p class="MsoPlainText" style="text-indent:.5in"><o:p> </o:p></p>
<p class="MsoPlainText">Thanks,<o:p></o:p></p>
<p class="MsoPlainText">Chuanbo Weng<o:p></o:p></p>
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