Date: Sun, 27 Jan 2008 20:54:00 -0500 From: "J.R. Oldroyd" <fbsd@opal.com> To: freebsd-x11@freebsd.org, freebsd-stable@freebsd.org, Thomas Dickey <dickey@radix.net>, eric@anholt.net Subject: Low CPU Freq responsible for xterm pixel corruption on RELENG_7 Message-ID: <20080127205400.0a59507d@linwhf.opal.com>
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--Sig_/WCBzRpJNPliuNunr_Ab_P+_ Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Some weeks ago, I posted on the x11@ list of a problem of pixel corruption I am seeing in xterm windows. An example of the problem can still be seen here: http://opal.com/jr/xterm-corruption.gif Quick summary: Wide xterm windows (wider than 158 columns, 1440 pixels) have the problem shown, but only when at least that many columns are on the screen. That is, moving a wide window so that it is partially off the screen causes the corruption to cease when less than 158 columns are displayed. Further investigation has unearthed that this problem happens only when the CPU frequency is set to low levels, which was happening because of powerd. When the CPU frequency is set low, these pixel corruptions happen. When the CPU freq is raised they do not: everything is normal. Disabling powerd and manually adjusting the CPU frequency gives these resul= ts: # sysctl dev.cpu.0.freq_levels dev.cpu.0.freq_levels: 3176/-1 2779/-1 2382/-1 1985/-1 1588/-1 1191/-1 794/= -1 397/-1 CPU freq from 3176 to 1191 causes no problems. CPU freq at 794 or 397 causes pixel corruptions. This problem did not happen on RELENG_6. -jr --Sig_/WCBzRpJNPliuNunr_Ab_P+_ Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFHnTW4ls33urr0k4kRAi91AJ9kFMJT6o5yVqE+sFHiVV0E0BavCwCfQ8xg lA9N8zDfUVB//044vfGvHeQ= =O9jf -----END PGP SIGNATURE----- --Sig_/WCBzRpJNPliuNunr_Ab_P+_--
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