On Tue, 30 May 2006, Jun OKAJIMA wrote: > Thank you for usuful advices. > > > > > Things like getting monitor information through DDC take > >a long time. Also, because clocks are being set there are > >PLL settling times that need to be observed least you mess > >things up by touching the hardware before the PLLs lock. > > > > I have heard about this issue, but, in my env, doing DDC probe is > very fast. It is done instantaneously. > Is DDC really a cause? > > > > > > > It may be that particular drivers have unnecessary waits here > >and there, but you really have to address them one by one, > >profiling to find the wait and then investigating whether or > >not it's really necessary. > > > > Then, the VESA driver of current XFree86 has unnecessary waits? > If so, I will try to get rid of. But, as far as I have glanced > the code, it just does call a VESA BIOS and it is all it does. > So, even there are unnecessary waits, they seems to be in a BIOS > code, I suppose. > > > > > > > I have worked on systems with boot times times on the order of > >a few seconds but these weren't trying to access VESA bios services > >or probing monitors through DDC. If you remove stuff like that, the > >boot times will probably be dominated by IDE probing, but then > >you end up having to hardcode things like monitor EDIDs that > >the driver would usually try to probe. > > > > Well, in MACH BOOT, it is possible to hard-code IDE params, > because most PCs has same param. But not possible to hard-code > DDC (EDID or...) because there are so many kind of monitor. > Any idea? You really just need to profile it and find where all the time is spent. If the video BIOS is doing all the initialization then it's likely that all the waiting is done there. It's undoubtedly all the monitor probing and clock setting and the associated delays and timeouts related to that. If the video card has multiple connectors it will probably be looking for devices on all connectors and trying that until it's convinced that it has found them all. Mark. _______________________________________________ XFree86 mailing list XFree86@xxxxxxxxxxx http://XFree86.Org/mailman/listinfo/xfree86
