Description:
pppd crashes when trying to establish a UMTS connection with wvdial. wvdial initializes the UMTS PCMCIA card and dials *99#. Right after wvdial launches pppd, I get the attached kernel trace.

wvdial-output:
# wvdial UMTS
--> WvDial: Internet dialer version 1.61
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ
ATZ
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Modem initialized.
--> Sending: ATDT*99#
--> Waiting for carrier.
ATDT*99#
CONNECT 1800000
--> Carrier detected. Waiting for prompt.
--> Don't know what to do! Starting pppd and hoping for the best.
--> Starting pppd at Sun Nov 22 13:13:02 2009
--> Pid of pppd: 1783
--> Using interface ppp0
--> pppd: [18]\[15][08]�i[15][08]
--> pppd: [18]\[15][08]�i[15][08]
--> pppd: [18]\[15][08]�i[15][08]
--> pppd: [18]\[15][08]�i[15][08]
--> pppd: [18]\[15][08]�i[15][08]
--> Disconnecting at Sun Nov 22 13:13:32 2009
--> The PPP daemon has died: A modem hung up the phone (exit code = 16)
--> man pppd explains pppd error codes in more detail.
--> Try again and look into /var/log/messages and the wvdial and pppd man pages for more information.
--> Auto Reconnect will be attempted in 5 seconds
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ

Additional info:
* kernel26 2.6.31.6-1
* wvdial 1.61-2
* ppp 2.4.4-9
* UMTS-Card: T-Mobile Mobile DSL Card 1800 (on the back it reads Qualcomm 3G CDMA, Model: GT 3G+ EMEA), using the nozomi driver

I tried various kernels, last working kernel is 2.6.28.10 (also getting a kernel trace, but the connection is established), 2.6.29.2 to 2.6.31 don't work.

kernel trace for not-working 2.6.31.6
------------[ cut here ]------------
WARNING: at kernel/mutex.c:435 mutex_trylock+0x122/0x140()
Hardware name: 1829DRG
Modules linked in: ppp_async ppp_generic ipv6 fan snd_seq_dummy snd_seq_oss nozomi snd_seq_midi_event snd_intel8x0m snd_seq snd_seq_device snd_intel8x0 snd_pcm_oss snd_mixer_oss pcmcia ipw2100 snd_ac97_codec libipw radeon ttm yenta_socket rsrc_nonstatic irtty_sir nsc_ircc sir_dev ohci1394 joydev ac97_bus pcmcia_core drm i2c_algo_bit snd_pcm thinkpad_acpi ieee1394 irda snd_timer lib80211 rfkill iTCO_wdt iTCO_vendor_support snd slhc psmouse intel_agp shpchp agpgart crc_ccitt ppdev soundcore snd_page_alloc i2c_i801 pci_hotplug led_class video nvram lp ac pcspkr output sg battery button parport_pc processor thermal i2c_core serio_raw evdev parport e1000 rtc_cmos rtc_core rtc_lib xfs exportfs uhci_hcd ehci_hcd sd_mod sr_mod cdrom floppy usbcore ata_piix ata_generic pata_acpi libata scsi_mod
Pid: 1707, comm: pppd Tainted: G W 2.6.31-ARCH #1
Call Trace:
[<c10464da>] ? warn_slowpath_common+0x7a/0xc0
[<c1306c32>] ? mutex_trylock+0x122/0x140
[<c1046540>] ? warn_slowpath_null+0x20/0x40
[<c1306c32>] ? mutex_trylock+0x122/0x140
[<f842ff45>] ? ntty_write+0x85/0x250 [nozomi]
[<f8384318>] ? xfs_iunlock+0xb8/0xd0 [xfs]
[<c10bc076>] ? find_get_page+0x36/0xe0
[<f8071cda>] ? ppp_async_push+0x3ca/0x4b0 [ppp_async]
[<f8071e01>] ? ppp_async_send+0x41/0x70 [ppp_async]
[<f811fa70>] ? ppp_channel_push+0x40/0xc0 [ppp_generic]
[<f811fbcf>] ? ppp_write+0xdf/0xf0 [ppp_generic]
[<c10f32c8>] ? vfs_write+0xc8/0x1c0
[<f811faf0>] ? ppp_write+0x0/0xf0 [ppp_generic]
[<c10f34df>] ? sys_write+0x5f/0xb0
[<c1003cb3>] ? sysenter_do_call+0x12/0x28
---[ end trace a7919e7f17c0a727 ]---

kernel trace for working 2.6.28.10:
Nov 22 12:49:18 p2x-555 kernel: ------------[ cut here ]------------
Nov 22 12:49:18 p2x-555 kernel: WARNING: at kernel/mutex.c:351 mutex_trylock+0xe0/0x130()
Nov 22 12:49:18 p2x-555 kernel: Modules linked in: ppp_async ppp_generic nozomi radeon drm ipv6 fan snd_intel8x0m snd_seq_oss snd_seq_midi_event snd_intel8x0 snd_seq snd_ac97_codec ac97_bus snd_seq_device pcmcia snd_pcm_oss snd_mixer_oss snd_pcm ohci1394 snd_timer yenta_socket rsrc_nonstatic ieee1394 snd pcmcia_core soundcore iTCO_wdt iTCO_vendor_support joydev ipw2100 thinkpad_acpi i2c_i801 video ieee80211 ieee80211_crypt irtty_sir rfkill snd_page_alloc i2c_core output slhc sir_dev nsc_ircc psmouse intel_agp ppdev shpchp led_class agpgart battery ac parport_pc pci_hotplug serio_raw irda pcspkr nvram lp evdev thermal crc_ccitt processor button sg parport e1000 rtc_cmos rtc_core rtc_lib xfs sr_mod cdrom uhci_hcd sd_mod ehci_hcd usbcore ata_piix ata_generic pata_acpi libata scsi_mod
Nov 22 12:49:18 p2x-555 kernel: Pid: 1969, comm: pppd Not tainted 2.6.28.10-ARCH #1
Nov 22 12:49:18 p2x-555 kernel: Call Trace:
Nov 22 12:49:18 p2x-555 kernel: [<c012e91f>] warn_on_slowpath+0x5f/0xa0
Nov 22 12:49:18 p2x-555 kernel: [<c016f999>] find_get_page+0x29/0xc0
Nov 22 12:49:18 p2x-555 kernel: [<c016fd1b>] find_lock_page+0x1b/0x60
Nov 22 12:49:18 p2x-555 kernel: [<c01703c5>] filemap_fault+0x235/0x470
Nov 22 12:49:18 p2x-555 kernel: [<c017f35a>] __do_fault+0x1fa/0x410
Nov 22 12:49:18 p2x-555 kernel: [<c032d150>] mutex_trylock+0xe0/0x130
Nov 22 12:49:18 p2x-555 kernel: [<f821fc43>] ntty_write+0x73/0x220 [nozomi]
Nov 22 12:49:18 p2x-555 kernel: [<c011fcb1>] do_page_fault+0x1b1/0x7b0
Nov 22 12:49:18 p2x-555 kernel: [<f832accb>] xfs_iunlock+0x9b/0xa0 [xfs]
Nov 22 12:49:18 p2x-555 kernel: [<f82c9b62>] ppp_async_push+0x3b2/0x4a0 [ppp_async]
Nov 22 12:49:18 p2x-555 kernel: [<f82c9c84>] ppp_async_send+0x34/0x50 [ppp_async]
Nov 22 12:49:18 p2x-555 kernel: [<f8181638>] ppp_channel_push+0x38/0x90 [ppp_generic]
Nov 22 12:49:18 p2x-555 kernel: [<f8181757>] ppp_write+0xc7/0xd0 [ppp_generic]
Nov 22 12:49:18 p2x-555 kernel: [<f8181690>] ppp_write+0x0/0xd0 [ppp_generic]
Nov 22 12:49:18 p2x-555 kernel: [<c0199d80>] vfs_write+0xa0/0x170
Nov 22 12:49:18 p2x-555 kernel: [<c0199f11>] sys_write+0x41/0x70
Nov 22 12:49:18 p2x-555 kernel: [<c0103eeb>] sysenter_do_call+0x12/0x2f
Nov 22 12:49:18 p2x-555 kernel: ---[ end trace 3e6512b12da73ce1 ]---

nozomi driver output:
Nov 22 13:22:43 p2x-555 kernel: nozomi 0000:03:00.0: Init, new card found
Nov 22 13:22:43 p2x-555 kernel: nozomi 0000:03:00.0: enabling device (0000 -> 0002)
Nov 22 13:22:43 p2x-555 kernel: nozomi 0000:03:00.0: PCI INT A -> Link[LNKA] -> GSI 11 (level, low) -> IRQ 11
Nov 22 13:22:43 p2x-555 kernel: nozomi 0000:03:00.0: Card type is: 2048
Nov 22 13:22:43 p2x-555 kernel: nozomi 0000:03:00.0: Version of card: 3
Nov 22 13:22:43 p2x-555 kernel: nozomi 0000:03:00.0: Initialization OK!
Nov 22 13:22:44 p2x-555 kernel: nozomi 0000:03:00.0: Device READY!


wvdial.conf:
[Dialer Defaults]
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = Analog Modem
ISDN = 0
Username = xxx
Init1 = ATZ
Password = xxx
check_carrier = no
Modem = /dev/noz0
Baud = 115200

[Dialer UMTS]
Phone = *99#

Steps to reproduce:
-Insert UMTS-Card
-wvdial UMTS