On Sunday, 21 of September 2008, Maxim Levitsky wrote: > Maxim Levitsky wrote: > > Rafael J. Wysocki wrote: > >> On Saturday, 20 of September 2008, Maxim Levitsky wrote: > >>> Hi, > >>> > >>> I hit a dead end when trying to understand why my notebook can't > >>> resume from suspend to ram > >>> if this is done two times a row. > >>> > >>> Single suspend/resume cycle works almost perfectly (beep that goes > >>> through the sound card is muted... no morse code for me... :-( > >>> > >>> ) > >>> > >>> I compiled a minimal kernel (absolutely nothing but disk drivers, all > >>> experimental option like nohz > >>> turned off) > >>> > >>> But I had to turn SMP, since without it system won't resume first > >>> time I suspend it. > >>> (How could this affect suspend?) > >> > >> It could if the system is 64-bit. In which case please have a look at > >> http://bugzilla.kernel.org/show_bug.cgi?id=11237 > >> > >>> With SMP and minimal kernel (of course no closed drivers), I get > >>> same behavior, > >>> first resume works second hangs. > >>> > >>> I then added some debug code to real mode wakeup code, I put there in > >>> first > >>> place instructions, that will save some magic value to rtc (to alarm > >>> registers that I know are preserved during boot cycle), and I > >>> discovered sad thing that first time bios does pass control to > >>> linux, but second time > >>> (when it hangs), it doesn't. > >>> > >>> I tried to update bios, and I got same results. > >>> > >>> Of course it does work with that @#$%^& OS > >> > >> So we're doing something wrong. Please try the appended patch. > > Thanks a lot, but this didn't help. > > > > It still has same pattern, first suspend/resume works perfectly, second > > suspend/resume hangs hard. > > It always happens like this, first resume always work (unless I turn off > > smp in kernel (I test this again), or reserve all low memory) > > > > Also note that if I suspend the system to ram, resume, and then suspend > > to disk, then I can suspend to ram and resume, it seems that > > > > on suspend to ram cycle somehow arms BIOS or something else, so second > > resume in a row doesn't work. > > > > I run 32 bit kernel here, this is a long story (this bios doesn't turn > > fan on when running 64-bit version, I could update it, and I know that > > fan issue is fixed there, but new bios introduces bigger bug, namely it > > makes fan to run almost always regardless of 32/64 type of os. > > And it doesn't fix this suspend/resume issue, I tested this. I could > > start/stop fan manually with a script, but this could fail, and maybe I > > will do so someday.) > > > > The bugzilla seems to be unrelated here, since bios does pass control > > there, but corrupts memory. > > Here I also have seen that bios corrupts memory, but everything resumes > > fine first time, and on second time, > > bios doesn't pass control (I put set of instructions in beginning of > > wakeup real mode assembly file, no page tables, GDT/LDT are used there) > > I did same test for kernel without SMP, yes it hangs on first resume, but bios > does pass control to linux, so while this is a minor bug, it is unrelated. Still, I'd be interested in debugging this one too, if possible. That may be easier too. ;-) > I also tested noapic, pci=nommconf. No luck. > > Pattern is always the same, first resume works always, second doesn't. > It is sad since first resume is almost perfect (when I have free time I need to look at sound codec datasheet > and fix few issues there, anyways here alsa has few issues, all this is trivial, I already fixed all issues with desktop > which has a sigmatel codec) If you have more than 2 GB of RAM, you can try iommu=soft . I guess that all of the /sys/power/pm_test tests are passed? Thanks, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
