Re: [PATCH] pci: fix unavailable irq number 255 reported by BIOS

[Sinan Kaya <okaya@codeaurora.org>]

On 1/19/2016 10:39 AM, Rafael J. Wysocki wrote:
> On Tue, Jan 19, 2016 at 3:48 PM, Sinan Kaya <okaya@codeaurora.org> wrote:
>> On 1/19/2016 9:20 AM, Rafael J. Wysocki wrote:
>>> On Tuesday, January 19, 2016 02:43:30 PM Rafael J. Wysocki wrote:
>>>> On Tuesday, January 19, 2016 09:45:13 AM Chen Fan wrote:
>>>>> In our environment, when enable Secure boot, we found an abnormal
>>>>> phenomenon as following call trace shows. after investigation, we
>>>>> found the firmware assigned an irq number 255 which means unknown
>>>>> or no connection in PCI local spec for i801_smbus, meanwhile the
>>>>> ACPI didn't configure the pci irq routing. and the 255 irq number
>>>>> was assigned for megasa msix without IRQF_SHARED. then in this case
>>>>> during i801_smbus probe, the i801_smbus driver would request irq with
>>>>> bad irq number 255. but the 255 irq number was assigned for memgasa
>>>>> with MSIX enable. which will cause request_irq fails, and call trace
>>>>> shows, actually, we should expose the error early, rather than in request
>>>>> irq, here we simply fix the problem by return err when find the irq is
>>>>> 255.
>>>>>
>>>>> See the call trace:
>>>>>
>>>>>  [   32.459195] ipmi device interface
>>>>>  [   32.612907] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4
>>>>>  [   32.800459] ixgbe: Intel(R) 10 Gigabit PCI Express Network Driver - version 4.0.1-k-rh
>>>>>  [   32.818319] ixgbe: Copyright (c) 1999-2014 Intel Corporation.
>>>>>  [   32.844009] lpc_ich 0001:80:1f.0: I/O space for ACPI uninitialized
>>>>>  [   32.850093] i801_smbus 0000:00:1f.3: enabling device (0140 -> 0143)
>>>>>  [   32.851134] i801_smbus 0000:00:1f.3: can't derive routing for PCI INT C
>>>>>  [   32.851136] i801_smbus 0000:00:1f.3: PCI INT C: no GSI
>>>>>  [   32.851164] genirq: Flags mismatch irq 255. 00000080 (i801_smbus) vs. 00000000 (megasa
>>>>>  [   32.851168] CPU: 0 PID: 2487 Comm: kworker/0:1 Not tainted 3.10.0-229.el7.x86_64 #1
>>>>>  [   32.851170] Hardware name: FUJITSU PRIMEQUEST 2800E2/D3736, BIOS PRIMEQUEST 2000 Serie5
>>>>>  [   32.851178] Workqueue: events work_for_cpu_fn
>>>>>  [   32.851208]  ffff88086c330b00 00000000e233a9df ffff88086d57bca0 ffffffff81603f36
>>>>>  [   32.851227]  ffff88086d57bcf8 ffffffff8110d23a ffff88686fe02000 0000000000000246
>>>>>  [   32.851246]  ffff88086a9a8c00 00000000e233a9df ffffffffa00ad220 0000000000000080
>>>>>  [   32.851247] Call Trace:
>>>>>  [   32.851261]  [<ffffffff81603f36>] dump_stack+0x19/0x1b
>>>>>  [   32.851271]  [<ffffffff8110d23a>] __setup_irq+0x54a/0x570
>>>>>  [   32.851282]  [<ffffffffa00ad220>] ? i801_check_pre.isra.5+0xe0/0xe0 [i2c_i801]
>>>>>  [   32.851289]  [<ffffffff8110d3bc>] request_threaded_irq+0xcc/0x170
>>>>>  [   32.851298]  [<ffffffffa00ae87f>] i801_probe+0x32f/0x508 [i2c_i801]
>>>>>  [   32.851308]  [<ffffffff81308385>] local_pci_probe+0x45/0xa0
>>>>>  [   32.851315]  [<ffffffff8108bfd4>] work_for_cpu_fn+0x14/0x20
>>>>>  [   32.851323]  [<ffffffff8108f0ab>] process_one_work+0x17b/0x470
>>>>>  [   32.851330]  [<ffffffff81090003>] worker_thread+0x293/0x400
>>>>>  [   32.851338]  [<ffffffff8108fd70>] ? rescuer_thread+0x400/0x400
>>>>>  [   32.851346]  [<ffffffff8109726f>] kthread+0xcf/0xe0
>>>>>  [   32.851353]  [<ffffffff810971a0>] ? kthread_create_on_node+0x140/0x140
>>>>>  [   32.851362]  [<ffffffff81613cfc>] ret_from_fork+0x7c/0xb0
>>>>>  [   32.851369]  [<ffffffff810971a0>] ? kthread_create_on_node+0x140/0x140
>>>>>  [   32.851373] i801_smbus 0000:00:1f.3: Failed to allocate irq 255: -16
>>>>>  [   32.851435] i801_smbus: probe of 0000:00:1f.3 failed with error -16
>>>>>  [   33.180145] ixgbe 0000:5a:00.0: Multiq[   33.240538] ixgbe 0000:5a:00.0: (PCI Express:03:e0
>>>>>  [   33.280826] ixgbe 0000:5a:00.0: MAC: 3, PHY: 0, PBA No: 000000-000
>>>>>
>>>>> Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
>>>>> ---
>>>>>  drivers/acpi/pci_irq.c | 10 +++++++++-
>>>>>  1 file changed, 9 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
>>>>> index d30184c..d2f47f8 100644
>>>>> --- a/drivers/acpi/pci_irq.c
>>>>> +++ b/drivers/acpi/pci_irq.c
>>>>> @@ -439,9 +439,17 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
>>>>>             if (acpi_isa_register_gsi(dev))
>>>>>                     dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
>>>>>                              pin_name(pin));
>>>>> +           rc = 0;
>>>>> +           /*
>>>>> +            * Excluding the BIOS report the value 255, which meaning
>>>>> +            * "unknown" or "no connection" in PCI Local Bus Specification
>>>>> +            * Revision 3.0 February 3, 2004, P223.
>>>>
>>>> You mean the footnote on page 223 talking about the Interrupt Line values, right?
>>
>> "Unknown" does not necessarily mean invalid. I have a platform that is using 255 as a valid legacy
>> interrupt on PCI Express.
> 
> So first off this is about the Interrupt Line value not about an
> interrupt vector.

Got it. Just to be clear, I assume this is not the value that code reads from the ACPI table. 

+		rc = dev->irq == 0xff ? -EINVAL : 0;

I was nervous to see this check in common code. 

> 
> Second, the footnote in question is talking about x86 PCs, so if your
> platform is not one of them, there is no connection here.
> 
> Which means that the change should be limited to x86 probably.
> 
> Thanks,
> Rafael
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-- 
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project