Thomas Renninger wrote: > On Mon, 2008-03-17 at 21:32 -0700, Arjan van de Ven wrote: >> Kevin Hunter wrote: >>> The more general, more on-topic issue is how to make sleep "just >>> work". That would save power in a less esoteric way than, say, the >>> tickless kernel. >> there's a few big steps forward coming soon; specifically, the graphic >> drivers >> are partially moving into the kernel. This allows for a not-insane way of >> doing >> suspend/resume for these, at least for those folks using the open drivers. >> >> Video is the big showstopper for suspend/resume right now; not only does it >> go >> wrong in graphics too often, not having graphics resumed also means you can't >> see printk's and other diagnostics, so other issues remain very well hidden >> ;( >> With this getting fixed in the next few months, I'm hoping there'll be a big >> jump >> in quality for S&R on Linux. > > How will this work? > Currently nearly all new laptops (even desktops) do suspend to ram > properly. The main problem is to detect whether the BIOS needs to be > posted. With an easy userspace workaround you get s2ram working on >90% > of recent laptops by trying out whether video posting is needed or not, > e.g. with these tools: http://sourceforge.net/projects/suspend
this is a bad hack though... the posting is fragile and .. kind of sometimes works. And so many things need to be alive for it to work (when it does) that it's not useful for diagnosing why the system doesn't even get to the part where userspace executes. > > It will get better, probably means the new in-kernel graphics things > popping up soon? > Will this solution: > A) Re-setup graphics settings so that storing (on suspend) and > re-writing (on resume) graphics cards parts are not needed at > all anymore (this is what "graphics cards posting" does, right?) it means the kernel can reinitialize the hardware entirely. Early during the resume. > B) Be able to detect whether posting is needed and do it it won't be needed. > > In case of A, the solution will be very hard to backport as huge driver > changes in kernel are needed (mode setting, etc.) well that's only for those who use really old distros. And the distro vendors who care about well working suspend/resume can do the work for this for their customers. In addition, it's generally a bad idea to not go for the right solution just because it's temporary harder to backport; distros rebase regularly (at least every year or two) while such technical solutions tend to live for much longer. _______________________________________________ Discuss mailing list [email protected] http://mail.lesswatts.org/mailman/listinfo/discuss
