Re: moxa serial driver testing

From: Sergei Organov
Date: Wed Dec 27 2006 - 06:14:50 EST

Jiri Slaby <jirislaby@xxxxxxxxx> writes:
> osv@xxxxxxxxx wrote:
>> Hi Jiri,
>> I've figured out that both old and new mxser drivers have two similar
>> problems:
>> 1. When there are data coming to a port, sometimes opening of the port
>> entirely locks the box. This is quite reproducible. Any idea what's
>> wrong and how can I help to debug it?
> Could you test the patch below, if something changes?

I've tested the latest version you've sent me yesterday. Still no
luck. The oops is below. I'll try with low_latency commented in a few

BUG: unable to handle kernel NULL pointer dereference at virtual address 00000068
printing eip:
*pde = 00000000
Oops: 0000 [#1]
Modules linked in: nvidia agpgart ipv6 nfs lockd nfs_acl sunrpc dm_mod sr_mod sbp2 ieee1394 ide_generic ide_disk e1000 snd_hda_intel snd_hda_codec snd_pcm_oss snd_mixer_oss i2c_i801 psmouse snd_pcm floppy tsdev serio_raw snd_timer parport_pc parport snd i2c_core pcspkr evdev soundcore snd_page_alloc mxser_new rtc ext3 jbd mbcache sd_mod ide_cd cdrom usb_storage usbhid ata_piix libata piix scsi_mod generic uhci_hcd ide_core usbcore skge thermal processor fan
CPU: 0
EIP: 0060:[<f8f3711f>] Tainted: P VLI
EFLAGS: 00010246 (2.6.18-3-686 #1)
EIP is at mxser_stoprx+0x54/0x74 [mxser_new]
eax: 00000000 ebx: 00000001 ecx: f8f3d79c edx: dfde7240
esi: f391211b edi: f4f83fff ebp: c1b17800 esp: f5bc7d7c
ds: 007b es: 007b ss: 0068
Process make (pid: 17088, ti=f5bc6000 task=f4febaa0 task.ti=f5bc6000)
Stack: 00000001 c01fe4af 000000ff f391201c c1b17c04 c011669e 00000000 00000000
00000003 00000096 c1b1780c 00000286 00000001 00000096 c01f97c9 00000000
f456f800 00000286 f8f38335 f5bc7e14 f8f3d8a8 00000286 c01f9806 f456f800
Call Trace:
[<c01fe4af>] n_tty_receive_buf+0xcd6/0xcf9
[<c011669e>] __wake_up+0x2a/0x3d
[<c01f97c9>] tty_ldisc_deref+0x50/0x5f
[<f8f38335>] mxser_receive_chars+0x241/0x249 [mxser_new]
[<c01f9806>] tty_ldisc_try+0x2e/0x32
[<c01f9d4c>] flush_to_ldisc+0x12f/0x15c
[<c01f9793>] tty_ldisc_deref+0x1a/0x5f
[<f8f38335>] mxser_receive_chars+0x241/0x249 [mxser_new]
[<f8f37678>] mxser_transmit_chars+0x14/0x164 [mxser_new]
[<c01f9d21>] flush_to_ldisc+0x104/0x15c
[<f8f38335>] mxser_receive_chars+0x241/0x249 [mxser_new]
[<f8f38d7a>] mxser_interrupt+0x15f/0x1e6 [mxser_new]
[<c013fb83>] handle_IRQ_event+0x23/0x49
[<c013fc3c>] __do_IRQ+0x93/0xe8
[<c01050e5>] do_IRQ+0x43/0x52
[<c01036b6>] common_interrupt+0x1a/0x20
[<c01bacf4>] __copy_from_user_ll+0x19/0x38
[<c01071de>] convert_fxsr_from_user+0x15/0xd5
[<c0164bc8>] pipe_read+0x0/0x1e
[<c010774e>] restore_i387+0x6f/0xc0
[<c0102203>] restore_sigcontext+0x10f/0x165
[<c0102b3d>] sys_sigreturn+0xa4/0xcb
[<c0102c7b>] syscall_call+0x7/0xb
Code: 83 e0 ee 89 41 3c 25 ee 00 00 00 42 eb 19 0f b6 42 1a 8b 51 08 89 41 38 31 c0 42 ee 89 d8 83 c8 02 89 41 3c 0f b6 c0 ee 8b 41 04 <8b> 40 68 83 78 08 00 79 15 8b 41 40 8b 51 08 83 e0 fd 89 41 40
EIP: [<f8f3711f>] mxser_stoprx+0x54/0x74 [mxser_new] SS:ESP 0068:f5bc7d7c
<0>Kernel panic - not syncing: Fatal exception in interrupt

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