<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">fyi<br><div><br><div>Begin forwarded message:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>From: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">Andy Green <<a href="mailto:andy@openmoko.com">andy@openmoko.com</a>></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Date: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">March 9, 2008 6:50:31 PM GMT+08:00</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>To: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">"Carsten Haitzler (The Rasterman)" <<a href="mailto:raster@openmoko.org">raster@openmoko.org</a>></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Cc: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">Wolfgang Spraul <<a href="mailto:wolfgang@openmoko.com">wolfgang@openmoko.com</a>>,<span class="Apple-converted-space"> </span>Sean Moss-Pultz <<a href="mailto:sean@openmoko.com">sean@openmoko.com</a>>, William Lai <<a href="mailto:will@openmoko.com">will@openmoko.com</a>>, "Tony Tu)" <<a href="mailto:tony@openmoko.com">tony@openmoko.com</a>>,<span class="Apple-converted-space"> </span>matt_hsu <<a href="mailto:matt_hsu@openmoko.org">matt_hsu@openmoko.org</a>>, Chia-I Wu <<a href="mailto:olv@openmoko.com">olv@openmoko.com</a>>, Werner Almesberger <<a href="mailto:werner@openmoko.org">werner@openmoko.org</a>></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Subject: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica"><b>Re: LCM flicker</b></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div> </div>-----BEGIN PGP SIGNED MESSAGE-----<br>Hash: SHA1<br><br>Somebody in the thread at some point said:<br><br><blockquote type="cite"><blockquote type="cite">hhmmm. then xrandr is lying to me, it claims 50hz. aqnd it claims 25hz for<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">landscape mode (which explains the much worse flicker).<br></blockquote></blockquote><br>It is true that landscape is 1/2 the rate of portrait currently, but 680<br>x 600 (the overscanned y and x) at 24.5MHz PCLK (41ns period) comes out<br>to 16.6ms == 60Hz.<br><br><blockquote type="cite">Either the refresh action we perform "beats" against another oscialltor<br></blockquote><blockquote type="cite">inside the LCM ("booster" or this "internal" osciallator), or there is<br></blockquote><blockquote type="cite">some kind of PWM trickery used to get the intensity levels that we beat<br></blockquote><blockquote type="cite">against somehow.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><blockquote type="cite">i haven't found a pathological pattern yet - but it seems a smooth gradient - in<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">ANY direction seems to bring it out. that doesn't help me figure out what kind<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">of pathological pattern is causing it. for that matter a solid orange color<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">region flickers too - all by itself. no gradient needed.<br></blockquote></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><blockquote type="cite">rgb: 255 145 0 does a wonder flickering job. this is totally bizarre unles u<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">look at there being some temporal interference pattern on the r & b signals<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">that doesn't affect g, and the interference pattern is inverted between r & b.<br></blockquote></blockquote><br>Hum well it is a big clue for sure since we can make the problem come<br>and go depending on colour. I guess the first question we should ask is<br>can the glamo being doing it really early in the actual pixel data frame<br>by frame. I will try to fill the display with this colour and have a look.<br><br>Another thing I noticed is that we have an insane RC filter on PCLK<br>currently, the signal quality on PCLK is pretty bad. But I can't make a<br>story how that causes these outcomes.<br><br>- -Andy<br>-----BEGIN PGP SIGNATURE-----<br>Version: GnuPG v1.4.7 (GNU/Linux)<br>Comment: Using GnuPG with Fedora - <a href="http://enigmail.mozdev.org">http://enigmail.mozdev.org</a><br><br>iD8DBQFH08D2OjLpvpq7dMoRApEdAKCWPfX4LSnNwqaQ+OyiOaa2+lVmPQCdEpBh<br>jxvF75pMXCa3C+SKUybbcUc=<br>=HXVy<br>-----END PGP SIGNATURE-----<br></blockquote></div><br></body></html>