From 2c6217e0fc5f6c7458f413346806061d97ce37cf Mon Sep 17 00:00:00 2001 From: Casey Leedom Date: Tue, 6 Aug 2013 15:48:37 +0530 Subject: PCI: Chelsio quirk: Enable Bus Master during Function-Level Reset T4 can wedge if there are DMAs in flight within the chip and Bus Master has been disabled. We need to have it on till the Function Level Reset completes. T4 can also suffer a Head Of Line blocking problem if MSI-X interrupts are disabled before the FLR has completed. Signed-off-by: Casey Leedom Signed-off-by: Vipul Pandya Signed-off-by: Bjorn Helgaas --- drivers/pci/quirks.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) (limited to 'drivers/pci/quirks.c') diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index e85d23044ae0..8f075a3cd805 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3208,6 +3208,83 @@ reset_complete: return 0; } +/* + * Device-specific reset method for Chelsio T4-based adapters. + */ +static int reset_chelsio_generic_dev(struct pci_dev *dev, int probe) +{ + u16 old_command; + u16 msix_flags; + + /* + * If this isn't a Chelsio T4-based device, return -ENOTTY indicating + * that we have no device-specific reset method. + */ + if ((dev->device & 0xf000) != 0x4000) + return -ENOTTY; + + /* + * If this is the "probe" phase, return 0 indicating that we can + * reset this device. + */ + if (probe) + return 0; + + /* + * T4 can wedge if there are DMAs in flight within the chip and Bus + * Master has been disabled. We need to have it on till the Function + * Level Reset completes. (BUS_MASTER is disabled in + * pci_reset_function()). + */ + pci_read_config_word(dev, PCI_COMMAND, &old_command); + pci_write_config_word(dev, PCI_COMMAND, + old_command | PCI_COMMAND_MASTER); + + /* + * Perform the actual device function reset, saving and restoring + * configuration information around the reset. + */ + pci_save_state(dev); + + /* + * T4 also suffers a Head-Of-Line blocking problem if MSI-X interrupts + * are disabled when an MSI-X interrupt message needs to be delivered. + * So we briefly re-enable MSI-X interrupts for the duration of the + * FLR. The pci_restore_state() below will restore the original + * MSI-X state. + */ + pci_read_config_word(dev, dev->msix_cap+PCI_MSIX_FLAGS, &msix_flags); + if ((msix_flags & PCI_MSIX_FLAGS_ENABLE) == 0) + pci_write_config_word(dev, dev->msix_cap+PCI_MSIX_FLAGS, + msix_flags | + PCI_MSIX_FLAGS_ENABLE | + PCI_MSIX_FLAGS_MASKALL); + + /* + * Start of pcie_flr() code sequence. This reset code is a copy of + * the guts of pcie_flr() because that's not an exported function. + */ + + if (!pci_wait_for_pending_transaction(dev)) + dev_err(&dev->dev, "transaction is not cleared; proceeding with reset anyway\n"); + + pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR); + msleep(100); + + /* + * End of pcie_flr() code sequence. + */ + + /* + * Restore the configuration information (BAR values, etc.) including + * the original PCI Configuration Space Command word, and return + * success. + */ + pci_restore_state(dev); + pci_write_config_word(dev, PCI_COMMAND, old_command); + return 0; +} + #define PCI_DEVICE_ID_INTEL_82599_SFP_VF 0x10ed #define PCI_DEVICE_ID_INTEL_IVB_M_VGA 0x0156 #define PCI_DEVICE_ID_INTEL_IVB_M2_VGA 0x0166 @@ -3221,6 +3298,8 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = { reset_ivb_igd }, { PCI_VENDOR_ID_INTEL, PCI_ANY_ID, reset_intel_generic_dev }, + { PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID, + reset_chelsio_generic_dev }, { 0 } }; -- cgit v1.2.3 From 4d708ab0c88512a3bea12f1ad68539fbe0d11d1a Mon Sep 17 00:00:00 2001 From: Casey Leedom Date: Tue, 6 Aug 2013 15:48:39 +0530 Subject: PCI: Use pci_wait_for_pending_transaction() instead of for loop New routine has been added to avoid duplication of code to wait for pending PCI transactions to complete. This makes use of that function. Signed-off-by: Casey Leedom Signed-off-by: Vipul Pandya Signed-off-by: Bjorn Helgaas --- drivers/pci/quirks.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-) (limited to 'drivers/pci/quirks.c') diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 8f075a3cd805..296508ec91d7 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3126,9 +3126,6 @@ static int reset_intel_generic_dev(struct pci_dev *dev, int probe) static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe) { - int i; - u16 status; - /* * http://www.intel.com/content/dam/doc/datasheet/82599-10-gbe-controller-datasheet.pdf * @@ -3140,20 +3137,9 @@ static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe) if (probe) return 0; - /* Wait for Transaction Pending bit clean */ - for (i = 0; i < 4; i++) { - if (i) - msleep((1 << (i - 1)) * 100); - - pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &status); - if (!(status & PCI_EXP_DEVSTA_TRPND)) - goto clear; - } - - dev_err(&dev->dev, "transaction is not cleared; " - "proceeding with reset anyway\n"); + if (!pci_wait_for_pending_transaction(dev)) + dev_err(&dev->dev, "transaction is not cleared; proceeding with reset anyway\n"); -clear: pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR); msleep(100); -- cgit v1.2.3