From: Bruce Allan Date: Sat, 9 Aug 2008 01:36:11 +0000 (-0700) Subject: e1000e: test for unusable MSI support X-Git-Tag: v2.6.27-rc4~39^2~48^2~17 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=f8d59f7826aa73c5e7682fbed6db38020635d466;p=linux-2.6-omap-h63xx.git e1000e: test for unusable MSI support 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 Signed-off-by: Jeff Kirsher Signed-off-by: Jeff Garzik --- diff --git a/drivers/net/e1000e/defines.h b/drivers/net/e1000e/defines.h index f823b8ba578..14b0e6cd3b8 100644 --- a/drivers/net/e1000e/defines.h +++ b/drivers/net/e1000e/defines.h @@ -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 */ diff --git a/drivers/net/e1000e/e1000.h b/drivers/net/e1000e/e1000.h index cf57050d99d..ac4e506b4f8 100644 --- a/drivers/net/e1000e/e1000.h +++ b/drivers/net/e1000e/e1000.h @@ -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])) diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c index b8b26cf78de..d266510c8a9 100644 --- a/drivers/net/e1000e/netdev.c +++ b/drivers/net/e1000e/netdev.c @@ -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);