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

[Rafael J. Wysocki]

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?

> +		 */
> +		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);