MPC8272- Porting HDLC driver from 2.6.14 to 2.6.27- "no_irq_chip" error

[Daniel Ng]

Hi,

I'm attempting to port our Ethos HDLC driver from 2.6.14 to 2.6.27, on
a MPC8272-based platform.

So far, the kernel crashes when the driver tries to open (see below).

It seems that the interrupt handler fails to register, with the
following condition in setup_irq() in manage.c:

desc->chip == &no_irq_chip

I notice that the only place where desc->chip is assigned to anything
else besides &no_irq_chip is in __set_irq_handler() in
kernel/irq/chip.c

In that file, __set_irq_handler() assigns desc->chip to
&dummy_irq_chip, but this seems to be done for a special ARM-specific
case, according to the commenting:

/*
 * Some ARM implementations install a handler for really dumb
 * interrupt hardware without setting an irq_chip. This worked
 * with the ARM no_irq_chip but the check in setup_irq would
 * prevent us to setup the interrupt at all. Switch it to
 * dummy_irq_chip for easy transition.
 */

Should I try to somehow call __set_irq_handler(), or should I be
looking elsewhere?

If I should be calling __set_irq_handler(), it seems the only relevant
function that calls this is cpm2_pic_host_map().

The only relevant functions which call cpm2_pic_host_map() are
irq_setup_virq() or irq_alloc_hosts() with the IRQ_HOST_MAP_LEGACY
parameter. IRQ_HOST_MAP_LEGACY seems to be irrelevant. Can someone
tell me what a virq is?

Cheers,
Daniel



Badness at c00224ec [verbose debug info unavailable]
NIP: c00224ec LR: c019b254 CTR: c01aa9f8
REGS: c1a49c70 TRAP: 0700   Not tainted  (2.6.27.19-800-OS-03050107)
MSR: 00021032 <ME,IR,DR>  CR: 22002022  XER: 00000000
TASK = c1bda400[306] 'pppd' THREAD: c1a48000
GPR00: 00000001 c1a49d20 c1bda400 00000000 c0318880 c19c4d80 c1b92211 00000000
GPR08: 00001032 c02cb240 00000000 00000000 22002022 fffffffe 01ff8000 00000000
GPR16: 10344020 00000000 00000002 10049ac0 c194f800 ffff8914 c18cd900 c18cd90c
GPR24: c1a49e48 00009032 c1a48000 c02b5fdc 00000002 c19c4d80 c1a48000 c1a48000
NIP [c00224ec] local_bh_enable+0x94/0xb4
LR [c019b254] dev_queue_xmit+0x108/0x580
Call Trace:
[c1a49d20] [c19c4d80] 0xc19c4d80 (unreliable)
[c1a49d30] [c019b254] dev_queue_xmit+0x108/0x580
[c1a49d50] [c016ac98] sppp_flush_xmit+0x20/0x44
[c1a49d60] [c016c0b4] sppp_open+0x80/0xac
[c1a49d80] [c016a104] ppp_open+0x70/0x98
--- Exception: bfd26bb0 at 0x8914
    LR = 0xc1a49e90
[c1a49da0] [c01699e0] hdlc_open+0x3c/0x104 (unreliable)
[c1a49dc0] [c016cdd4] ethos_wan_genhdlc_open+0xb0/0xef8
[c1a49df0] [c019c490] dev_open+0xbc/0x120
[c1a49e00] [c019bbc8] dev_change_flags+0x8c/0x1d0
[c1a49e20] [c01e1678] devinet_ioctl+0x700/0x7ac
[c1a49e90] [c01e2538] inet_ioctl+0xcc/0xf8
[c1a49ea0] [c018b584] sock_ioctl+0x60/0x268
[c1a49ec0] [c0084ab0] vfs_ioctl+0x3c/0xc4
[c1a49ee0] [c0084bb8] do_vfs_ioctl+0x80/0x454
[c1a49f10] [c0084fcc] sys_ioctl+0x40/0x88
[c1a49f40] [c000f928] ret_from_syscall+0x0/0x38
--- Exception: c01 at 0x480af50c
    LR = 0x480af5e4
Instruction dump:
41a20008 482044e1 80010014 83e1000c 38210010 7c0803a6 4e800020 3d20c02d
3929b240 800900dc 7c000034 5400d97e <0f000000> 2f800000 41beff90 38000001
hdlc2: Carrier detected
setup_irq()- desc->chip == &no_irq_chip
request_irq()- setup_irq() FAILED
ethos_wan_genhdlc_open(): request_irq() FAILED! ethos_wan->io_addr: 0xc5080000