Bug 12777

Summary:	ath5k: unaligned access on mips
Product:	Networking	Reporter:	Bob Copeland (me)
Component:	Wireless	Assignee:	networking_wireless (networking_wireless)
Status:	RESOLVED INSUFFICIENT_DATA
Severity:	normal	CC:	me, satishs85
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.29	Subsystem:
Regression:	No	Bisected commit-id:

Description Bob Copeland 2009-02-25 07:33:56 UTC

(Moved from bug 12647)

But when i do wget from some other system the board reboots displaying
the following error:

Unhandled kernel unaligned access[#1]:
Cpu 0
$ 0   : 00000000 7fcfbb60 fbd3efbe 802778a0
$ 4   : 802778a0 000000d0 00000000 0000002f
$ 8   : 87b98f80 80064610 87afc000 fffffff8
$12   : 00000000 00000000 00000000 00000000
$16   : fbd3efbe 00000001 000000d0 8014116c
$20   : 00000080 2ac31030 00000000 00000101
$24   : 00000000 2ab9efb0

Comment 1 Bob Copeland 2009-02-25 07:47:07 UTC

Ok, that sort of helps, but what I would really like to see is something like this:

Code:Unhandled kernel unaligned access[#2]:
Cpu 0
$ 0   : 0000000000000000 000000001004cce0 6775696c65332c1c 0000000000000000
$ 4   : ffffffff8800c8f8 6775696c65332c14 ffffffff8800aba4 ffffffffbfbd9830
$ 8   : ffffffff8835fb00 0000000000000034 ffffffff89d13700 0000000000000000
$12   : 000000001004cce0 000000001000001e 0000000000000038 0000000000000003
$16   : ffffffff89d13700 ffffffff8c430000 0000000000000010 ffffff0000000000
$20   : ffffffff88310000 ffffffff880c8de8 0000000000000000 ffffffff883dca58
$24   : ffffffff89d135d5 ffffffff88173398
$28   : ffffffff89d10000 ffffffff89d136d0 ffffffff883e0000 ffffffff88006420
Hi    : 0000000000000039
Lo    : ba5e353f7cea6200
epc   : ffffffff8800c910 do_ade+0x300/0x480     Not tainted
ra    : ffffffff88006420 ret_from_exception+0x0/0x24
Status: 1004cce2    KX SX UX KERNEL EXL
Cause : 10008410
BadVA : 6775696c65332c14
PrId  : 00000460 (R4400SC)
Modules linked in: ipv6
Process dpkg (pid: 1193, threadinfo=ffffffff89d10000, task=ffffffff8bdb5810, tls=000000002aad1ac0)
Stack : fffffffffffffffd 0000000000000000 0000000000000000 6775696c65332c20
        ffffffff88006420 0000000000000015 0000000000000000 000000001004cce0
        6775696c65332c14 0000000000000000 0000000000000000 ffffffff88360000
        00000000000006e5 ffffffffbfbd9830 ffffffff8835fb00 0000000000000034
        0000000000002a7a ffffffff883e0000 ffffffff883e0000 ffffffff883e0000
        0000000000000038 0000000000000003 fffffffffffffffd 0000000000000000
        0000000000000000 6775696c65332c20 ffffffff88310000 ffffffff880c8de8
        0000000000000000 ffffffff883dca58 ffffffff89d135d5 ffffffff88173398
        ffffffff89d137f8 67653a2062617474 ffffffff89d10000 ffffffff89d13830
        ffffffff883e0000 ffffffff8800aadc 000000001004cce2 0000000000000039
        ...
Call Trace:
[<ffffffff8800c910>] do_ade+0x300/0x480
[<ffffffff88006420>] ret_from_exception+0x0/0x24
[<ffffffff8800aba8>] show_code+0xf8/0x138
[<ffffffff8800b8f8>] show_registers+0x58/0x70
[<ffffffff8800b990>] die+0x80/0x100
[<ffffffff8800ca58>] do_ade+0x448/0x480
[<ffffffff88006420>] ret_from_exception+0x0/0x24

Code: 00621824  5460ffbd  de020100 <88b20000> 98b20003  24020000  1440ffe8  00000000  0a003217

Ideally you should be able to capture that on a serial console.  You will need CONFIG_STACKTRACE at least (select Kernel Debugging when configuring the kernel).  Otherwise, all we know is what is in the CPU registers but not what part of the code is performing the unaligned access.

Comment 2 Bob Copeland 2009-03-27 01:55:12 UTC

The original reporter of this disappeared, will reopen if he has more info.

Comment 3 satish 2009-03-30 18:45:53 UTC

(In reply to comment #2)
> The original reporter of this disappeared, will reopen if he has more info.

sorry for not updating the status. i have been out of my work for a month.

I changed the DMA_SIZE to 4B. now the processor does not restart when i do wget.