Re: [BUG] 2.6.25-rc3 hangs in early boot on Sun Ultra5

[Mikael Pettersson <mikpe@it.uu.se>]

Mikael Pettersson writes:
 > Booting 2.6.25-rc3 on my Ultra5 causes a hang before or as
 > the console is switched over to the framebuffer. The console
 > output is (extrapolated from dmesg in -rc2 and handwritten
 > notes, as I don't have a serial cable to my U5):
 > 
 > PROMLIB: Sun IEEE Boot Prom 'OBP 3.25.3 2000/06/29 14:12'
 > PROMLIB: Root node compatible: 
 > *** the following line can't be seen in dmesg after rc2 has booted
 > console [earlyprom0] enabled
 > Linux version 2.6.25-rc3 (mikpe@sparge) (gcc version 4.2.3) #1 Mon Feb 25 18:49:41 CET 2008
 > ARCH: SUN4U
 > Ethernet address: 08:00:20:fd:ec:1f
 > [0000000200000000-fffff80000400000] page_structs=262144 node=0 entry=0/0
 > [0000000200000000-fffff80000800000] page_structs=262144 node=0 entry=1/0
 > [0000000200000000-fffff80000c00000] page_structs=262144 node=0 entry=2/0
 > [0000000200000000-fffff80001000000] page_structs=262144 node=0 entry=3/0
 > OF stdout device is: /pci@1f,0/pci@1,1/SUNW,m64B@2
 > PROM: Built device tree with 46617 bytes of memory.
 > On node 0 totalpages: 32299
 >   Normal zone: 335 pages used for memmap
 >   Normal zone: 0 pages reserved
 >   Normal zone: 31964 pages, LIFO batch:7
 >   Movable zone: 0 pages used for memmap
 > Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 31964
 > Kernel command line: ro root=/dev/sda5
 > PID hash table entries: 1024 (order: 10, 8192 bytes)
 > clocksource: mult[28000] shift[16]
 > clockevent: mult[66666666] shift[32]
 > Console: colour dummy device 80x25
 > *** the following line can't be seen in dmesg after rc2 has booted
 > console handover: boot [earlyprom0] -> real [tty0]
 > 
 > At this point rc3 hangs hard and won't even respond to sysrq.
 > 
 > Another difference is that with rc2 the first few lines of kernel
 > output while the console is still in OF mode either aren't shown
 > or disappear quickly since the switch to the framebuffer occurs
 > within a fraction of a second after the kernel has been loaded.
 > With rc3 the kernel output (the text shown above) in the OF-mode
 > console is very very slow.
 > 
 > (I should have quoted my .config here but I forgot to bring it.
 > It's exactly the same in rc2 and rc3, however.)
 > 
 > I'll try some rc2->rc3 bisecting later.

Minor update: rc2-git7 has the slow initial console behaviour,
but successfully switches to the framebuffer. rc2-git8 however
hangs in the console handover. So I'll bisect git7->git8 next.

/Mikael