ALSA MIDI serial u16550 horribly broken in 2.6.4

From: Dave Jones
Date: Mon Mar 15 2004 - 11:16:08 EST

poking io port 0x1 probably isn't going to do much good.
Here's what happens after a 'modprobe snd_serial_u16550'


u16550: can't grab port 0x1
no UART detected at 0x1
Unable to handle kernel NULL pointer dereference at virtual address 00000020
printing eip:
*pde = 00000000
Oops: 0000 [#1]
CPU: 0
EIP: 0060:[<c788b38f>] Not tainted
EFLAGS: 00010246 (2.6.4-prep)
EIP is at snd_info_unregister+0x5/0x60 [snd]
eax: 00000000 ebx: c1286b1c ecx: 00000000 edx: 00000000
esi: 00000000 edi: c1286b59 ebp: c1286b40 esp: c21cef4c
ds: 007b es: 007b ss: 0068
Process modprobe (pid: 8679, threadinfo=c21ce000 task=c37a0ce0)
Stack: c1286b1c fffffff0 c1286b59 c7889c6d 00000000 c78991f6 c1286b59 c1286b40
c78073f3 00009600 0001c200 00000000 00000000 c7807490 c1286b1c 00000000
00000000 00000000 c031bbd8 c21ce000 c78074b4 c031bbf8 c789ac00 c0138fad
Call Trace:
[<c7889c6d>] snd_card_free+0x163/0x1ed [snd]
[<c78073f3>] snd_serial_probe+0x12a/0x1de [snd_serial_u16550]
[<c7807490>] snd_serial_probe+0x1c7/0x1de [snd_serial_u16550]
[<c78074b4>] alsa_card_serial_init+0xd/0x34 [snd_serial_u16550]
[<c0138fad>] sys_init_module+0x14f/0x25f
[<c02c4567>] syscall_call+0x7/0xb

Code: 8b 40 20 85 c0 74 05 8b 78 34 eb 06 8b 3d 2c 5f 89 c7 bb 90

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