I've got a Redhat 6.2 box here with a HiSax PCI ISDN card (modprobed with parameters: type=36 protocol=2). It's running a custom compiled 2.2.17 kernel. If I do an "isdnctrl dial ippp0" it dials up and negotiates the IP address, etc. However, I can't transmit any data across the syncppp link - whenever I try to ping the remote peer, I get: isdn_ppp: No compressor set! ippp: no decompressor defined! Fairly frequently when I send data across the syncppp link, I get either an Oops or a panic (see below). From what I can tell from the call trace, the oops happens in udp_recvmsg and the panic happens in net_bh. Has anyone got any ideas how I can fix it, or is it a major bug with the kernel and not going to work any time soon? (If it's a problem with that particular card, I can go out and buy a new card, so that's not too much of a problem). --- OOPS --- Unable to handle kernel NULL pointer dereference at virtual address 00000004 current->tss.cr3 = 00aee000, %cr3 = 00aee000 *pde = 00000000 Oops: 0002 CPU: 0 EIP: 0010:[<c014aa67>] EFLAGS: 00010046 eax: c38ea720 ebx: c0375184 ecx: 00000246 edx: 00000000 esi: c0aedeec edi: c0375140 ebp: c0375184 esp: c0aeddf4 ds: 0018 es: 0018 ss: 0018 Process ping (pid: 778, process nr: 41, stackpage=c0aed000) Stack: 00000000 c0aedf6c c0aede40 c0375184 00000000 c0375140 c0166929 c0375140 00000000 00000000 c0aede48 00000000 c0375140 c0aedf6c c0aedf6c dd43a1d5 c743a1d5 c0aedec8 3aebd833 c743a1d5 c0aede48 00000000 c016b0e0 c0375140 Call Trace: [<c0166929>] [<c016b0e0>] [<c0147c62>] [<c016b06c>] [<c01487c8>] [< [<c01104d3>] [<c011035e>] [<c0147ee3>] [<c0148ef7>] [<c0108fc0>] Code: 89 5a 04 89 13 c7 00 00 00 00 00 c7 40 04 00 00 00 00 c7 40 ------- --- PANIC --- Unable to handle kernel NULL pointer dereference at virtual address 00000040 current->tss.cr3 = 00101000, %cr3 = 00101000 *pde = 00000000 Oops: 0000 CPU: 0 EIP: 0010:[<c0157668>] EFLAGS: 00010217 eax: 00000000 ebx: c38eaa40 ecx: 00000000 edx: c38eaa40 esi: c0ada0f4 edi: 00000014 ebp: c01ddf40 esp: c01ddf2c ds: 0018 es: 0018 ss: 0018 Process swapper (pid: 0, process nr: 0, stackpage=c01dd000) Stack: c38eaa40 c01d3274 c38eaa40 00000002 00000001 c38eaa40 c014bf65 c38eaa40 c3c9038c c01d3274 00000001 c01ffce4 0001a82e c01ddf94 0001a82f 0008df94 c01178fd c01dc000 00000000 c0110555 00000001 c01dc000 0001a82e 00000018 Call Trace: [<c014bf65>] [<c01178fd>] [<c0110555>] [<c010784d>] [<c0107855>] [< [<c0108fc0>] [<c0106000>] [<c010607b>] [<c0106000>] [<c0100175>] Code: 8b 40 40 ff d0 83 c4 04 eb 20 89 f6 ff 05 0c 32 1d c0 8b 55 Aiee, killing interrupt handler Kernel panic: Attempted to kill the idle task! In swapper task - not syncing ------- -- - Steve Hill System Administrator Email: [EMAIL PROTECTED] Navaho Technologies Ltd. Tel: +44-870-7034015 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/