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

From: Sinan Kaya
Date: Tue Jan 19 2016 - 09:49:27 EST

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@xxxxxxxxxxxxxx>
>>> ---
>>> 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.

>>
>>> + */
>>> + if (dev->irq == 0xFF)
>>> + rc = -EINVAL;
>>>
>>> kfree(entry);
>>> - return 0;
>>> + return rc;
>>> }
>>>
>>> rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
>>>
>>
>> Well, if you look at acpi_isa_register_gsi(), you'll see that it
>> actually does the check you're adding, so maybe the following should
>> be done instead?
>>
>> ---
>> drivers/acpi/pci_irq.c | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> Index: linux-pm/drivers/acpi/pci_irq.c
>> ===================================================================
>> --- linux-pm.orig/drivers/acpi/pci_irq.c
>> +++ linux-pm/drivers/acpi/pci_irq.c
>> @@ -436,12 +436,13 @@ int acpi_pci_irq_enable(struct pci_dev *
>> * driver reported one, then use it. Exit in any case.
>> */
>> if (gsi < 0) {
>> - if (acpi_isa_register_gsi(dev))
>> + rc = acpi_isa_register_gsi(dev);
>> + if (rc)
>> dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
>> pin_name(pin));
>>
>> kfree(entry);
>> - return 0;
>> + return rc;
>> }
>>
>> rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
>>
>> --
>
> Alternatively, to be entirely on the safe side and avoid possible regressions
> from returning errors when they were not returned previously, we can
> just special case the 0xff value as you did, but in a slightly cleaner way:
>

Is the issue limited to ISA? If yes, can we limit the change with ISA/PCI adapters only?

Is there a way to know if the system is PCIe vs. PCI?

> ---
> drivers/acpi/pci_irq.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> Index: linux-pm/drivers/acpi/pci_irq.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/pci_irq.c
> +++ linux-pm/drivers/acpi/pci_irq.c
> @@ -436,12 +436,18 @@ int acpi_pci_irq_enable(struct pci_dev *
> * driver reported one, then use it. Exit in any case.
> */
> if (gsi < 0) {
> - if (acpi_isa_register_gsi(dev))
> + /*
> + * The Interrupt Line value of 0xff is defined to mean "unknown"
> + * or "no connection" (PCI 3.0, Section 6.2.4, footnote on page
> + * 223), so return an error in that case.
> + */
> + rc = dev->irq == 0xff ? -EINVAL : 0;
> + if (rc || acpi_isa_register_gsi(dev))
> dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
> pin_name(pin));
>
> kfree(entry);
> - return 0;
> + return rc;
> }
>
> rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
>
> --
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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