Ah, the serial console needed to be reset.  Here's a proper stack trace.

[ 6024.913665] kernel BUG at /build/buildd/linux-linaro-2.6.35/drivers/video/oma
p2/dss/core.c:323!
[ 6024.927551] Unable to handle kernel NULL pointer dereference at virtual addre
ss 00000000
[ 6024.940643] pgd = ce4c0000
[ 6024.948333] [00000000] *pgd=00000000
[ 6024.956970] Internal error: Oops: 805 [#1]
[ 6024.966064] last sysfs file: /sys/kernel/uevent_seqnum
[ 6024.976226] Modules linked in: nls_iso8859_1 nls_cp437 vfat fat asix musb_hdrc usbnet leds_gpio omap_wdt omap2_mcspi led_class joydev gpio_keys twl4030_usb twl4030_pwrbutton usbhid hid
[ 6025.003662] CPU: 0    Not tainted  (2.6.35-1004-linaro-omap #9-Ubuntu)
[ 6025.015655] PC is at __bug+0x24/0x2c
[ 6025.024627] LR is at release_console_sem+0x84/0xc4
[ 6025.034790] pc : [<c0046ba4>]    lr : [<c0081254>]    psr: 60000013
[ 6025.034820] sp : cdd55d58  ip : c0769094  fp : cdd55d64
[ 6025.057128] r10: 00000000  r9 : cdd54000  r8 : 00000003
[ 6025.067749] r7 : c02d47f4  r6 : cdd55dd8  r5 : 00000000  r4 : 00000003
[ 6025.079742] r3 : 00000000  r2 : c072d8f8  r1 : 7df0760c  r0 : 00000069
[ 6025.091705] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[ 6025.104248] Control: 10c5387d  Table: 8e4c0019  DAC: 00000015
[ 6025.115447] Process halt (pid: 744, stack limit = 0xcdd542e8)
[ 6025.126617] Stack: (0xcdd55d58 to 0xcdd56000)
[ 6025.136383] 5d40:                                                       cdd55d7c cdd55d68
[ 6025.150024] 5d60: c02cdabc c0046b8c fa050400 c0721b10 cdd55d94 cdd55d80 c02d8710 c02cda30
[ 6025.163787] 5d80: c0062678 c0721b10 cdd55dac cdd55d98 c02e00e8 c02d86f4 c02e0110 c0721b10
[ 6025.177642] 5da0: cdd55dc4 cdd55db0 c02e0124 c02e00cc c02e0110 00000000 cdd55dd4 cdd55dc8
[ 6025.191589] 5dc0: c02d4818 c02e011c cdd55dfc cdd55dd8 c03107d8 c02d4800 cec58738 ce6341b0
[ 6025.205505] 5de0: c0721fb8 c0721fc4 c0818a74 4321fedc cdd55e0c cdd55e00 c02d4a44 c031077c
[ 6025.219421] 5e00: cdd55e1c cdd55e10 c02ccdd0 c02d4a2c cdd55e2c cdd55e20 c0312598 c02ccdb8
[ 6025.233367] 5e20: cdd55e4c cdd55e30 c030d0bc c0312584 c0769028 00000002 4321fedc c076908c
[ 6025.247375] 5e40: cdd55e64 cdd55e50 c0097314 c030d05c fee1dead 00000000 cdd55e74 cdd55e68
[ 6025.261413] 5e60: c0097484 c00972e4 cdd55fa4 cdd55e78 c009768c c009747c ceda0c70 c072d358
[ 6025.275482] 5e80: 00000000 00000000 00000200 c0042280 c050c10c c006ca18 ffffffff cdece01c
[ 6025.289550] 5ea0: cee70780 ceda0c40 cdd55ed4 cdd55eb8 c007b924 c0104e40 fffff
[ 6025.303588] 5ec0: ceda6200 ceda0c40 cdd55f2c cdd55ed8 c0507b3c c007b8f0 c007cc5c 00000007
[ 6025.317657] 5ee0: c0717f34 401783cc cdd55fb0 00000006 00000000 40022f3c cdd55fac cdd55f08
[ 6025.331756] 5f00: c0042280 c050bca4 cec02440 c073c28c cdd55f8c c016757c cdd54000 cec02600
[ 6025.345825] 5f20: cdd55f44 cdd55f30 c0507ef0 c0507864 cdd12440 cdd12440 cdd12400 cdd12440
[ 6025.359893] 5f40: cdd55f5c cdd55f50 00000000 cdd12400 cdd55f84 cdd55f60 c0144ab4 c01447d4
[ 6025.373931] 5f60: cdd55f8c 00000002 00000000 00000024 c0042c68 00000000 cdd55fa4 7df0760c
[ 6025.387878] 5f80: c01675f8 40022f3c 00000002 00000000 00000058 c0042c68 00000000 cdd55fa8
[ 6025.401763] 5fa0: c0042ac0 c0097510 40022f3c 00000002 fee1dead 28121969 4321fedc 00000003
[ 6025.415618] 5fc0: 40022f3c 00000002 00000000 00000058 00000006 00000000 40022f3c 00000000
[ 6025.429443] 5fe0: 00000058 bef4bcac 402213ad 4019a896 00000030 fee1dead 00000000 00000000
[ 6025.443237] [<c0046ba4>] (__bug+0x24/0x2c) from [<c02cdabc>] (dss_clk_disable+0x98/0xa8)
[ 6025.456878] [<c02cdabc>] (dss_clk_disable+0x98/0xa8) from [<c02d8710>] (omapdss_dpi_display_disable+0x28/0x44)
[ 6025.472534] [<c02d8710>] (omapdss_dpi_display_disable+0x28/0x44) from [<c02e00e8>] (generic_panel_power_off+0x28/0x2c)
[ 6025.488922] [<c02e00e8>] (generic_panel_power_off+0x28/0x2c) from [<c02e0124>] (generic_panel_disable+0x14/0x20)
[ 6025.504791] [<c02e0124>] (generic_panel_disable+0x14/0x20) from [<c02d4818>] (dss_disable_device+0x24/0x2c)
[ 6025.520233] [<c02d4818>] (dss_disable_device+0x24/0x2c) from [<c03107d8>] (bus_for_each_dev+0x68/0x94)
[ 6025.535308] [<c03107d8>] (bus_for_each_dev+0x68/0x94) from [<c02d4a44>] (dss_disable_all_devices+0x24/0x28)
[ 6025.550933] [<c02d4a44>] (dss_disable_all_devices+0x24/0x28) from [<c02ccdd0>] (omap_dss_shutdown+0x24/0x38)
[ 6025.566741] [<c02ccdd0>] (omap_dss_shutdown+0x24/0x38) from [<c0312598>] (platform_drv_shutdown+0x20/0x24)
[ 6025.582244] [<c0312598>] (platform_drv_shutdown+0x20/0x24) from [<c030d0bc>] (device_shutdown+0x6c/0xac)
[ 6025.597473] [<c030d0bc>] (device_shutdown+0x6c/0xac) from [<c0097314>] (kernel_shutdown_prepare+0x3c/0x40)
[ 6025.612915] [<c0097314>] (kernel_shutdown_prepare+0x3c/0x40) from [<c0097484>] (kernel_halt+0x14/0x2c)
[ 6025.628021] [<c0097484>] (kernel_halt+0x14/0x2c) from [<c009768c>] (sys_reboot+0x188/0x220)
[ 6025.642242] [<c009768c>] (sys_reboot+0x188/0x220) from [<c0042ac0>] (ret_fast_syscall+0x0/0x30)
[ 6025.656799] Code: e3010908 e34c0061 eb130294 e3a03000 (e5833000)
[ 6025.671752] OMAPFB: pan_display(0)
[ 6025.681060] OMAPFB: setcmap
[ 6025.689666] OMAPFB: setcmap
[ 6025.709869] OMAPFB: setcmap
[ 6025.718292] ---[ end trace 1096c166fcefe505 ]---
Segmentation fault