matroxfb-fix-dvi-setup-to-be-more-compatible.patch introduces jitter
I've been looking deeper into this problem, which was reportedly introduced by my patch a while ago, in Linux kernel 2.6.17. I don't doubt the reports, but I'd like to replicate the problem as seen on the x86 boxes as reported in kernel bug 6720 and a few others directly to me, so I can verify a fix (if/when I can create one).
So, I installed SLES 10 on an old x86 box, with a PCI G450 (actually an IBM GXT135P). I verified that my patch is _not_ included in that kernel (2.6.16.21). However, I see jittery DVI-D output at all times. I've tried 640x480@60Hz, 1280x1024@60Hz, different "vesa" mode parameters (0x11b, 0x1bb), XServer "-fbbpp 32". I usually end up losing sync with the monitor after a few minutes.
I don't have much experience with the G450 on x86, but I'm quite surprised. Has anyone else observed this?
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Regards, Paul Clarke ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
Quoted 13 lines · Paul A. Clarke
I've been looking deeper into this problem, which was reportedly introduced by my patch a while ago, in Linux kernel 2.6.17. I don't doubt the reports, but I'd like to replicate the problem as seen on the x86 boxes as reported in kernel bug 6720 and a few others directly to me, so I can verify a fix (if/when I can create one).
So, I installed SLES 10 on an old x86 box, with a PCI G450 (actually an IBM GXT135P). I verified that my patch is _not_ included in that kernel (2.6.16.21). However, I see jittery DVI-D output at all times. I've tried 640x480@60Hz, 1280x1024@60Hz, different "vesa" mode parameters (
0x11b,0x1bb), XServer "-fbbpp 32". I usually end up losing sync with the monitor after a few minutes.
Quoted 2 lines
I don't have much experience with the G450 on x86, but I'm quite surprised. Has anyone else observed this?
I believe that problem is not x86 vs. ppc, but type of monitor you have connected to the box.
Perhaps try walkdvi
(http://platan.vc.cvut.cz/ftp/pub/linux/matrox-latest/walkdvi.tar.gz, it will probably need some fixes for big endian) with different XDVICLKCTL values. Code to set XPANMODE (in g450_set_plls) was written based on experimenting with couple of devices I had, so maybe right thing is not modifying XDVICLKCTL register, but instead teaching PLL code to try different XPANMODE values if PLL does not lock in reasonable time.
Petr
-------------------------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642