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e1000e: test for unusable MSI support

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Some systems do not like 82571/2 use of 16-bit MSI messages and some
other systems claim to support MSI, but neither really works.  Setup a
test MSI handler to detect whether or not MSI is working properly, and
if not, fallback to legacy INTx interrupts.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Bruce Allan 2008-08-08 18:36:11 -07:00 committed by Jeff Garzik
parent d53f706da8
commit f8d59f7826
3 changed files with 164 additions and 11 deletions
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2
drivers/net/e1000e/defines.h
View File

@ -389,7 +389,7 @@
/* Interrupt Cause Set */
#define E1000_ICS_LSC E1000_ICR_LSC /* Link Status Change */
#define E1000_ICS_RXDMT0 E1000_ICR_RXDMT0 /* rx desc min. threshold */
#define E1000_ICS_RXSEQ E1000_ICR_RXSEQ /* Rx sequence error */
#define E1000_ICS_RXDMT0 E1000_ICR_RXDMT0 /* Rx desc min. threshold */
/* Transmit Descriptor Control */

1
drivers/net/e1000e/e1000.h
View File

@ -326,6 +326,7 @@ struct e1000_info {
#define FLAG_RX_CSUM_ENABLED (1 << 28)
#define FLAG_TSO_FORCE (1 << 29)
#define FLAG_RX_RESTART_NOW (1 << 30)
#define FLAG_MSI_TEST_FAILED (1 << 31)
#define E1000_RX_DESC_PS(R, i) \
(&(((union e1000_rx_desc_packet_split *)((R).desc))[i]))

172
drivers/net/e1000e/netdev.c
View File

@ -1236,26 +1236,36 @@ static irqreturn_t e1000_intr(int irq, void *data)
return IRQ_HANDLED;
}
/**
* e1000_request_irq - initialize interrupts
*
* Attempts to configure interrupts using the best available
* capabilities of the hardware and kernel.
**/
static int e1000_request_irq(struct e1000_adapter *adapter)
{
struct net_device *netdev = adapter->netdev;
irq_handler_t handler = e1000_intr;
int irq_flags = IRQF_SHARED;
int err;
if (!pci_enable_msi(adapter->pdev)) {
adapter->flags |= FLAG_MSI_ENABLED;
handler = e1000_intr_msi;
irq_flags = 0;
if (!(adapter->flags & FLAG_MSI_TEST_FAILED)) {
err = pci_enable_msi(adapter->pdev);
if (!err) {
adapter->flags |= FLAG_MSI_ENABLED;
irq_flags = 0;
}
}
err = request_irq(adapter->pdev->irq, handler, irq_flags, netdev->name,
netdev);
err = request_irq(adapter->pdev->irq,
((adapter->flags & FLAG_MSI_ENABLED) ?
&e1000_intr_msi : &e1000_intr),
irq_flags, netdev->name, netdev);
if (err) {
e_err("Unable to allocate %s interrupt (return: %d)\n",
adapter->flags & FLAG_MSI_ENABLED ? "MSI":"INTx", err);
if (adapter->flags & FLAG_MSI_ENABLED)
if (adapter->flags & FLAG_MSI_ENABLED) {
pci_disable_msi(adapter->pdev);
adapter->flags &= ~FLAG_MSI_ENABLED;
}
e_err("Unable to allocate interrupt, Error: %d\n", err);
}
return err;
@ -2594,6 +2604,135 @@ err:
return -ENOMEM;
}
/**
* e1000_intr_msi_test - Interrupt Handler
* @irq: interrupt number
* @data: pointer to a network interface device structure
**/
static irqreturn_t e1000_intr_msi_test(int irq, void *data)
{
struct net_device *netdev = data;
struct e1000_adapter *adapter = netdev_priv(netdev);
struct e1000_hw *hw = &adapter->hw;
u32 icr = er32(ICR);
e_dbg("%s: icr is %08X\n", netdev->name, icr);
if (icr & E1000_ICR_RXSEQ) {
adapter->flags &= ~FLAG_MSI_TEST_FAILED;
wmb();
}
return IRQ_HANDLED;
}
/**
* e1000_test_msi_interrupt - Returns 0 for successful test
* @adapter: board private struct
*
* code flow taken from tg3.c
**/
static int e1000_test_msi_interrupt(struct e1000_adapter *adapter)
{
struct net_device *netdev = adapter->netdev;
struct e1000_hw *hw = &adapter->hw;
int err;
/* poll_enable hasn't been called yet, so don't need disable */
/* clear any pending events */
er32(ICR);
/* free the real vector and request a test handler */
e1000_free_irq(adapter);
/* Assume that the test fails, if it succeeds then the test
* MSI irq handler will unset this flag */
adapter->flags |= FLAG_MSI_TEST_FAILED;
err = pci_enable_msi(adapter->pdev);
if (err)
goto msi_test_failed;
err = request_irq(adapter->pdev->irq, &e1000_intr_msi_test, 0,
netdev->name, netdev);
if (err) {
pci_disable_msi(adapter->pdev);
goto msi_test_failed;
}
wmb();
e1000_irq_enable(adapter);
/* fire an unusual interrupt on the test handler */
ew32(ICS, E1000_ICS_RXSEQ);
e1e_flush();
msleep(50);
e1000_irq_disable(adapter);
rmb();
if (adapter->flags & FLAG_MSI_TEST_FAILED) {
err = -EIO;
e_info("MSI interrupt test failed!\n");
}
free_irq(adapter->pdev->irq, netdev);
pci_disable_msi(adapter->pdev);
if (err == -EIO)
goto msi_test_failed;
/* okay so the test worked, restore settings */
e_dbg("%s: MSI interrupt test succeeded!\n", netdev->name);
msi_test_failed:
/* restore the original vector, even if it failed */
e1000_request_irq(adapter);
return err;
}
/**
* e1000_test_msi - Returns 0 if MSI test succeeds or INTx mode is restored
* @adapter: board private struct
*
* code flow taken from tg3.c, called with e1000 interrupts disabled.
**/
static int e1000_test_msi(struct e1000_adapter *adapter)
{
int err;
u16 pci_cmd;
if (!(adapter->flags & FLAG_MSI_ENABLED))
return 0;
/* disable SERR in case the MSI write causes a master abort */
pci_read_config_word(adapter->pdev, PCI_COMMAND, &pci_cmd);
pci_write_config_word(adapter->pdev, PCI_COMMAND,
pci_cmd & ~PCI_COMMAND_SERR);
err = e1000_test_msi_interrupt(adapter);
/* restore previous setting of command word */
pci_write_config_word(adapter->pdev, PCI_COMMAND, pci_cmd);
/* success ! */
if (!err)
return 0;
/* EIO means MSI test failed */
if (err != -EIO)
return err;
/* back to INTx mode */
e_warn("MSI interrupt test failed, using legacy interrupt.\n");
e1000_free_irq(adapter);
err = e1000_request_irq(adapter);
return err;
}
/**
* e1000_open - Called when a network interface is made active
* @netdev: network interface device structure
@ -2652,6 +2791,19 @@ static int e1000_open(struct net_device *netdev)
if (err)
goto err_req_irq;
/*
* Work around PCIe errata with MSI interrupts causing some chipsets to
* ignore e1000e MSI messages, which means we need to test our MSI
* interrupt now
*/
{
err = e1000_test_msi(adapter);
if (err) {
e_err("Interrupt allocation failed\n");
goto err_req_irq;
}
}
/* From here on the code is the same as e1000e_up() */
clear_bit(__E1000_DOWN, &adapter->state);