when try to kexec one latest kernel from kernel.org from RHEL 5.1 got

ACPI: PCI Interrupt 0000:02:00.0[A] -> Link [LNKA] -> GSI 19 (level, low) -> IRQ 19
acpi->mptable 2 : Int: type 0, pol 1, trig 1, bus 02, IRQ 00, APIC ID 0, APIC INT 13
PCI: Setting latency timer of device 0000:02:00.0 to 64
PCI: Enabling Mem-Wr-Inval for device 0000:02:00.0
scsi0 :  on PCI bus 02 device 00 irq 19
irq 19: nobody cared (try booting with the "irqpoll" option)
Pid: 1, comm: swapper Not tainted 2.6.24-smp-07682-g551e4fb-dirty #19

Call Trace:
 <IRQ>  [<ffffffff8026a3eb>] __report_bad_irq+0x30/0x72
 [<ffffffff8026a651>] note_interrupt+0x224/0x26f
 [<ffffffff8026ae78>] handle_fasteoi_irq+0xa5/0xc8
 [<ffffffff8021ffdc>] call_softirq+0x1c/0x28
 [<ffffffff802218e2>] do_IRQ+0xf1/0x15f
 [<ffffffff8021f361>] ret_from_intr+0x0/0xa
 <EOI>  [<ffffffff80785bd6>] pci_mmcfg_write+0x0/0xb0
 [<ffffffff80224dd9>] native_read_tsc+0xd/0x1d
 [<ffffffff804681e7>] __delay+0x17/0x22
 [<ffffffff805cb1a9>] lpfc_sli_brdrestart+0x14c/0x16b
 [<ffffffff805cb264>] lpfc_do_config_port+0x9c/0x3e4
 [<ffffffff802d77a9>] sysfs_link_sibling+0x17/0x31
 [<ffffffff805cb674>] lpfc_sli_hba_setup+0xc8/0x4a2
 [<ffffffff80825397>] lpfc_pci_probe_one+0x750/0x914
 [<ffffffff804728f3>] pci_device_probe+0xb3/0xfb
 [<ffffffff804d958c>] driver_probe_device+0xb5/0x132
 [<ffffffff804d96ab>] __driver_attach+0x0/0x93
 [<ffffffff804d9705>] __driver_attach+0x5a/0x93
 [<ffffffff804d89bc>] bus_for_each_dev+0x44/0x6f
 [<ffffffff804d91b9>] bus_add_driver+0xae/0x1f5
 [<ffffffff804d990e>] driver_register+0x59/0xce
 [<ffffffff80472b56>] __pci_register_driver+0x4a/0x7c
 [<ffffffff80c2d78a>] lpfc_init+0x98/0xba
 [<ffffffff80c0d6e7>] kernel_init+0x175/0x2e1
 [<ffffffff8021fc68>] child_rip+0xa/0x12
 [<ffffffff80c0d572>] kernel_init+0x0/0x2e1
 [<ffffffff8021fc5e>] child_rip+0x0/0x12

handlers:
[<ffffffff805cdbce>] (lpfc_intr_handler+0x0/0x4c6)
Disabling IRQ #19

root caused that there is one Intel card that shared io apic pin and irq with
 ...
[ message continues ]

Any pci_* call before pci_enable_device() is questionable.  I would put 
it after pci_enable_device(), unless there is a _strong_ reason.

PCI devices are not considered available, with resources assigned, until 
pci_enable_device()

I am also curious what irq events are being raised?  That seems like 
another problem area to address, since pci_intx() is just a band-aid 
hiding that behavior.

	Jeff


--

[ message continues ]

YH
--

[ message continues ]

pci_intx should be safe.

void
pci_intx(struct pci_dev *pdev, int enable)
{
        u16 pci_command, new;

        pci_read_config_word(pdev, PCI_COMMAND, &pci_command);

        if (enable) {
                new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
        } else {
                new = pci_command | PCI_COMMAND_INTX_DISABLE;
        }

        if (new != pci_command) {
                struct pci_devres *dr;

                pci_write_config_word(pdev, PCI_COMMAND, new);

                dr = find_pci_dr(pdev);
                if (dr && !dr->restore_intx) {
                        dr->restore_intx = 1;
                        dr->orig_intx = !enable;
                }
        }
}

static struct pci_devres * find_pci_dr(struct pci_dev *pdev)
{
        if (pci_is_managed(pdev))
                return devres_find(&pdev->dev, pcim_release, NULL, NULL);
        return NULL;
}


YH
--

[ message continues ]

try to solve
	troubles with r8169
	http://lkml.org/lkml/2007/8/12/225

same to
	[PATCH] e1000: fix IRQx nobody cared for shared irq with INTx
	http://lkml.org/lkml/2008/3/29/103

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>

diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index 3acfeea..7405a95 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -1619,6 +1619,8 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	tp->dev = dev;
 	tp->msg_enable = netif_msg_init(debug.msg_enable, R8169_MSG_DEFAULT);
 
+	/* disable INTx at first */
+	pci_intx(pdev, 0);
 	/* enable device (incl. PCI PM wakeup and hotplug setup) */
 	rc = pci_enable_device(pdev);
 	if (rc < 0) {
@@ -1887,6 +1889,11 @@ static int rtl8169_open(struct net_device *dev)
 	if (retval < 0)
 		goto err_release_ring_2;
 
+	if (!(tp->features & RTL_FEATURE_MSI)) {
+		/* enable INTx if not using MSI */
+		pci_intx(pdev, 1);
+        }
+
 #ifdef CONFIG_R8169_NAPI
 	napi_enable(&tp->napi);
 #endif
--

[ message continues ]

[PATCH] ixgb/e: fix IRQx nobody cared for shared irq with INTx

solve
	ixgb on pci-x and mptsas on pci-x. sometime mptsas get confused.

same to
	[PATCH] e1000: fix IRQx nobody cared for shared irq with INTx
	http://lkml.org/lkml/2008/3/29/103

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>

Index: linux-2.6/drivers/net/ixgb/ixgb_main.c
===================================================================
--- linux-2.6.orig/drivers/net/ixgb/ixgb_main.c
+++ linux-2.6/drivers/net/ixgb/ixgb_main.c
@@ -290,6 +290,11 @@ ixgb_up(struct ixgb_adapter *adapter)
 #endif
 	ixgb_irq_enable(adapter);
 
+	if (!adapter->have_msi) {
+		/* enable INTx if not using MSI */
+		pci_intx(adapter->pdev, 1);
+	}
+
 	return 0;
 }
 
@@ -368,6 +373,8 @@ ixgb_probe(struct pci_dev *pdev,
 	int i;
 	int err;
 
+	/* disable INTx at first */
+	pci_intx(pdev, 0);
 	if((err = pci_enable_device(pdev)))
 		return err;
 
Index: linux-2.6/drivers/net/ixgbe/ixgbe_main.c
===================================================================
--- linux-2.6.orig/drivers/net/ixgbe/ixgbe_main.c
+++ linux-2.6/drivers/net/ixgbe/ixgbe_main.c
@@ -1988,6 +1988,12 @@ try_intr_reinit:
 	if (err)
 		goto err_up;
 
+	if (!(adapter->flags &
+	      (IXGBE_FLAG_MSI_ENABLED | IXGBE_FLAG_MSIX_ENABLED))) {
+		/* enable INTx if not using MSI/MSIX */
+		pci_intx(adapter->pdev, 1);
+	}
+
 	return 0;
 
 err_up:
@@ -2627,6 +2633,8 @@ static int __devinit ixgbe_probe(struct 
 	u16 link_status, link_speed, link_width;
 	u32 part_num;
 
+	/* disable INTx at first */
+	pci_intx(pdev, 0);
 	err = pci_enable_device(pdev);
 	if (err)
 		return err;
--

[ message continues ]