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 @#$%^& OS > > So we're doing something wrong. Please try the appended patch. > >> I then proceeded to test recently posted low memory corruption patch, and >> it did show that that @#$%^& BIOS does corrupt low memory >> I then reserved all low memory, but system began to hand after first suspend, >> in exactly same way, but as expected I soon discovered, that that forces real >> mode page to be above 1M, ok, then I reserved almost all low memory except >> 100K window in the middle, so low allocations will work, but be placed in >> region bios less likely to corrupt, and still that didn't help, still same hang. >> More information, I compiled kernels back to 2.6.19, and they all have exactly the same issue. Any ideas? Best regards, Maxim Levitsky _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
