Re: [git pull] drm next tree

From: Jiri Kosina
Date: Thu Jan 30 2014 - 10:55:23 EST


On Thu, 30 Jan 2014, Dave Airlie wrote:

> git://people.freedesktop.org/~airlied/linux drm-next
[ ... snip ... ]
> Daniel Vetter (59):
[ ... snip ... ]
> drm/i915: dp aux irq support for g4x/vlv

This commit causes all kinds of havoc on my ThinkPad x200s. It results in

irq 16: nobody cared (try booting with the "irqpoll" option)
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.12.0-00854-g4aeebd7 #1
Hardware name: LENOVO 7470BN2/7470BN2, BIOS 6DET38WW (2.02 ) 12/19/2008
ffff8800795186c0 ffff88007c203e08 ffffffff81582503 ffff88007c203e38
ffffffff810a6a98 ffff88007c203e88 ffff880079518600 0000000000000000
0000000000000010 ffff88007c203e78 ffffffff810a6d43 00000010ffc4af9d
Call Trace:
<IRQ> [<ffffffff81582503>] dump_stack+0x7a/0x97
[<ffffffff810a6a98>] __report_bad_irq+0x38/0xf0
[<ffffffff810a6d43>] note_interrupt+0x1f3/0x240
[<ffffffff810a42d2>] handle_irq_event_percpu+0x142/0x220
[<ffffffff810a43f9>] handle_irq_event+0x49/0x70
[<ffffffff810a7561>] handle_fasteoi_irq+0x61/0x100
[<ffffffff81004a89>] handle_irq+0x59/0x150
[<ffffffff81052b6e>] ? _local_bh_enable+0xe/0x10
[<ffffffff81052bf1>] ? irq_enter+0x81/0x90
[<ffffffff8100403b>] do_IRQ+0x5b/0xe0
[<ffffffff81588aaf>] common_interrupt+0x6f/0x6f
<EOI> [<ffffffff81588b5c>] ? retint_restore_args+0xe/0xe
[<ffffffff8146c767>] ? poll_idle+0x47/0x90
[<ffffffff8146c740>] ? poll_idle+0x20/0x90
[<ffffffff810acd96>] ? ktime_get+0x56/0xd0
[<ffffffff8146c7f0>] cpuidle_enter_state+0x40/0xd0
[<ffffffff8146cc0a>] cpuidle_idle_call+0x10a/0x160
[<ffffffff8100b7b9>] arch_cpu_idle+0x9/0x30
[<ffffffff810a370b>] cpu_idle_loop+0x8b/0x270
[<ffffffff810a390e>] cpu_startup_entry+0x1e/0x20
[<ffffffff8157a0c3>] rest_init+0xd3/0xe0
[<ffffffff81579ff0>] ? csum_partial_copy_generic+0x170/0x170
[<ffffffff81ad905c>] start_kernel+0x3b3/0x461
[<ffffffff81ad8a96>] ? repair_env_string+0x58/0x58
[<ffffffff81ad84d1>] x86_64_start_reservations+0x1b/0x32
[<ffffffff81ad8622>] x86_64_start_kernel+0x13a/0x141
handlers:
[<ffffffffa00acbc0>] usb_hcd_irq [usbcore]
Disabling IRQ #16

and things go south afterwards (the machine hangs randomly, I/O is
horribly slow, etc etc).

This is the same machine that was the reason for

commit c12aba5aa0e60b7947bc8b6ea25ef55c4acf81a4
Author: Jiri Kosina <jkosina@xxxxxxx>
Date: Tue Mar 19 09:56:57 2013 +0100

drm/i915: stop using GMBUS IRQs on Gen4 chips

back then in 3.9 timeframe, so it might be somehow related. It's, at the
end of the day, again IRQ 16 -- and see the changelog of c12aba5a why this
is rather mysterious (IRQ 16 is assigned to the card when it's not using
MSI, but it *is* in fact using MSI in all the cases).

--
Jiri Kosina
SUSE Labs

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