Re: [PATCH] PCI: export MSI mode using attributes, not kobjects

[Bjorn Helgaas]

On Thu, Dec 12, 2013 at 7:06 PM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Thu, Dec 12, 2013 at 04:56:20PM -0700, Bjorn Helgaas wrote:
>> On Thu, Dec 12, 2013 at 4:17 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>> > On Sat, Dec 7, 2013 at 12:41 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
>> >> On Wed, Nov 27, 2013 at 11:46 AM, Greg Kroah-Hartman
>> >> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>> >>> From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>> >>>
>> >>> The PCI MSI sysfs code is a mess with kobjects for things that don't
>> >>> really need to be kobjects.  This patch creates attributes dynamically
>> >>> for the MSI interrupts instead of using kobjects.
>> >>>
>> >>> Note, this removes a directory from the current MSI interrupt sysfs
>> >>> code:
>> >>>
>> >>> old MSI kobjects:
>> >>> pci_device
>> >>>    âââ msi_irqs
>> >>>        âââ 40
>> >>>            âââ mode
>> >>>
>> >>> new MSI attributes:
>> >>> pci_device
>> >>>    âââ msi_irqs
>> >>>        âââ 40
>> >>>
>> >>> As there was only one file "mode" with the kobject model, the interrupt
>> >>> number is now a file that returns the "mode" of the interrupt (msi vs.
>> >>> msix).
>> >>>
>> >>> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>> >>
>> >> I added the acks from Neil and Veaceslav, folded in the
>> >> Documentation/ABI update, and applied the whole thing to my pci/misc
>> >> branch for v3.14.  Thanks!
>> >
>> > got:
>> > [   71.429735] BUG: key ffff887fcf082a58 not in .data!
>> > [   71.429737] ------------[ cut here ]------------
>> > [   71.429742] WARNING: CPU: 0 PID: 4 at kernel/locking/lockdep.c:2987 lockdep_i
>> > nit_map+0x127/0x5b0()
>> > [   71.429743] DEBUG_LOCKS_WARN_ON(1)
>> > [   71.429744] Modules linked in:
>> > [   71.429747] CPU: 0 PID: 4 Comm: kworker/0:0 Tainted: G          I  3.13.0-rc3
>> > -yh-01187-ge0e4e4e-dirty #45
>> > [   71.429757] Workqueue: events work_for_cpu_fn
>> > [   71.429792]  0000000000000009 ffff881fcf95da58 ffffffff82020475 ffff881fcf95d
>> > aa0
>> > [   71.429800]  ffff881fcf95da90 ffffffff81097c3d ffff887fcf082a58 ffff88dfcec1a
>> > d28
>> > [   71.429809]  0000000000000000 0000000000000000 ffff889fcf2eecd0 ffff881fcf95d
>> > af0
>> > [   71.429809] Call Trace:
>> > [   71.429814]  [<ffffffff82020475>] dump_stack+0x45/0x56
>> > [   71.429818]  [<ffffffff81097c3d>] warn_slowpath_common+0x7d/0xa0
>> > [   71.429822]  [<ffffffff81097cac>] warn_slowpath_fmt+0x4c/0x50
>> > [   71.429826]  [<ffffffff810e3d97>] lockdep_init_map+0x127/0x5b0
>> > [   71.429835]  [<ffffffff81242fe8>] ? sysfs_new_dirent+0x98/0x140
>> > [   71.429839]  [<ffffffff81242033>] sysfs_add_file_mode_ns+0x63/0xc0
>> > [   71.429843]  [<ffffffff8124491d>] internal_create_group+0x18d/0x260
>> > [   71.429853]  [<ffffffff81556345>] ? populate_msi_sysfs+0x185/0x1d0
>> > [   71.429857]  [<ffffffff81244a52>] sysfs_create_groups+0x42/0xa0
>> > [   71.429861]  [<ffffffff81556367>] populate_msi_sysfs+0x1a7/0x1d0
>> > [   71.429865]  [<ffffffff81556b67>] pci_enable_msi_block+0x1f7/0x2a0
>> > [   71.429870]  [<ffffffff81549795>] pcie_port_device_register+0x335/0x520
>> > [   71.429874]  [<ffffffff81549f08>] pcie_portdrv_probe+0x68/0xa0
>> > [   71.429883]  [<ffffffff8153cf75>] local_pci_probe+0x45/0xa0
>> > [   71.429887]  [<ffffffff810b0af4>] work_for_cpu_fn+0x14/0x20
>> > [   71.429891]  [<ffffffff810b431b>] process_one_work+0x28b/0x4a0
>> > [   71.429895]  [<ffffffff810b4292>] ? process_one_work+0x202/0x4a0
>> > [   71.429899]  [<ffffffff810b55db>] worker_thread+0x26b/0x3a0
>> > [   71.429903]  [<ffffffff810e262d>] ? trace_hardirqs_on+0xd/0x10
>> > [   71.429906]  [<ffffffff810b5370>] ? manage_workers.isra.17+0x340/0x340
>> > [   71.429912]  [<ffffffff810bc031>] kthread+0x111/0x120
>> > [   71.429919]  [<ffffffff810cddab>] ? local_clock+0x2b/0x40
>> > [   71.429923]  [<ffffffff810bbf20>] ? kthread_stop+0xf0/0xf0
>> > [   71.429927]  [<ffffffff8203842c>] ret_from_fork+0x7c/0xb0
>> > [   71.429931]  [<ffffffff810bbf20>] ? kthread_stop+0xf0/0xf0
>> > [   71.429933] ---[ end trace c511e3d74efea94e ]---
>> >
>> > looks like Greg forgot adding attr init.
>> >
>> > Can you fold attached patch into Greg's patch ?
>>
>> Sure.  I don't know how to reproduce it, so I couldn't verify the fix,
>> but I added it to Greg's patch.  Thanks!
>
> I think lockdep has to be enabled for this to show up, I wasn't running
> with that enabled when I tested the code, my fault, sorry.

No problem.  I have

CONFIG_LOCKDEP_SUPPORT=y
CONFIG_LOCKDEP=y
CONFIG_DEBUG_LOCKDEP=y

and I still don't see the problem booting the qemu q35 model.
Whatever, I folded it in anyway.

Bjorn
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