2010/3/30 Michel Dänzer <mic...@daenzer.net>: > On Tue, 2010-03-30 at 05:34 +0100, Dave Airlie wrote: >> >> Original pull req below + reverts the fallback placement change which had >> a side effect of causing more lockups on some AGP systems (this is a bug in >> the AGP drivers that needs to be tracked down), [...] > > While I was able to work around the lockups by making the AGP driver > never unbind a GTT entry, I think it's rather a radeon issue - how is > the AGP driver supposed to know when it's safe to unbind an entry?
This issue has been a problem with AGP before, the Intel AGP docs claim you should always use scratch pages on AGP, and never complete remove bound entries. I've no idea why this is, as you'd expect AGP cards to only generate cycles to entries they've been asked to. There may be some memory controller prefetching going on that could lead to prefetching into an unbound AGP page and the resulting machine check that may cause I suppose. We need to track this separately anyways and fix it for 2.6.35 hopefully, at least we have a patch that can handle it. > That change had lots of other issues anyway, thanks for reverting it. > > >> [...] and I've merged Jerome's GPU recovery code, as I'd much rather >> users had some of hope of recovering from their GPU locking up than a >> dead box. It seems to work for quite a lot of people that have tested >> it, and it won't make a GPU lockup problem worse. > > Unfortunately, that's not true in all cases. The change itself mentions > that the new reset code is unreliable for R3xx generation GPUs, and > indeed with my RV350 it now turns my box into a brick immediately on a > GPU lockup most of the time whereas previously it was usually able to > recover at least in some cases, e.g. falling back to PCI mode after > trying to use a non-working AGP transfer mode. > Okay so it makes it worse, hopefully Jerome can track it down, or else we can lock down the gpu reset to only trying on the r600s where it definitely makes life a lot better for everyone. Dave. ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel