On Fre, 2002-11-01 at 13:09, Simon Richter wrote: > > On Fri, Nov 01, 2002 at 02:46:29PM +0000, J.D. Hood wrote: > > The question was: Why does X need APM support in order > > to recover from a suspend-and-resume cycle? > > Yes, and the short answer to this is that this is actually pointless. X > already receives VT_ACTIVATE and VT_DEACTIVATE events,
I don't think it does, at least 'on PPC'. That's (part of) the problem. > > If the OS lacks APM support, then it is completely > > unaware of APM events such as suspending and resuming, > > There are still the other PM standards, like ACPI on i386/ia64, the Mac > standard on PowerPC etc. That's why APM support will not help the > PowerPC people (in fact, nothing will; see below). Wrong, see below. > > which is implemented in firmware. The OS can't switch > > from X to the console, because nothing tells it that > > a suspend is about to happen, or has happened. So far > > as the OS is concerned, all that happens is that the > > real time clock jumps ahead. > > Actually we have unified PM in the kernel now, which means that we have > a single routine which all PM modules will call on suspend. I'm going to > check back with the kernel code whether the VT switch still happens or > if that got lost in the transition to unified PM and if necessary, lobby > for its re-inclusion. It shouldn't be necessary, X can handle this internally for the PM standards it supports (currently only APM). > > Of course, because firmware rarely restores everything > > exactly to its pre-suspend state, some other things > > are different too ... and herein lies the cause of the > > hangs. > > Which is the PowerPC problem. The init sequence for the graphics > hardware is a well-kept secret, so in fact the kernel would have to call > the firmware init, but for some reason (I'm not too deep into that) this > doesn't work. This isn't needed normally 'on PPC'. > > To cure the problem on powerpc it will not suffice > > to install the powermgmt-base package. All that > > does (after getting the administrator's permission) is > > create /dev/apm_bios (via MAKEDEV) if the node doesn't > > exist already exist. It also configures modutils > > and devfs for APM. But powermgmt-base doesn't add APM > > support to a kernel that lacks it. > > Which would be complete and utter BS, since PPC doesn't have APM. We do have APM emulation for Macs, /dev/apm_bios works if that's enabled in the kernel. -- Earthling Michel Dänzer (MrCooper)/ Debian GNU/Linux (powerpc) developer XFree86 and DRI project member / CS student, Free Software enthusiast -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
