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Commit 13aa6ecb authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by Roland Dreier
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IB/mthca: restore missing PCI registers after reset 



mthca does not restore the following PCI-X/PCI Express registers after reset:
  PCI-X device: PCI-X command register
  PCI-X bridge: upstream and downstream split transaction registers
  PCI Express : PCI Express device control and link control registers

This causes instability and/or bad performance on systems where one of
these registers is set to a non-default value by BIOS.

Signed-off-by: default avatarMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 427abfa2

drivers/infiniband/hw/mthca/mthca_reset.c

+59 −0
Original line number Diff line number Diff line
@@ -49,6 +49,12 @@ int mthca_reset(struct mthca_dev *mdev) 
	u32 *hca_header    = NULL;

	u32 *bridge_header = NULL;

	struct pci_dev *bridge = NULL;

	int bridge_pcix_cap = 0;

	int hca_pcie_cap = 0;

	int hca_pcix_cap = 0;



	u16 devctl;

	u16 linkctl;



#define MTHCA_RESET_OFFSET 0xf0010

#define MTHCA_RESET_VALUE  swab32(1)
@@ -110,6 +116,9 @@ int mthca_reset(struct mthca_dev *mdev) 
		}

	}



	hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);

	hca_pcie_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP);



	if (bridge) {

		bridge_header = kmalloc(256, GFP_KERNEL);

		if (!bridge_header) {
@@ -129,6 +138,13 @@ int mthca_reset(struct mthca_dev *mdev) 
				goto out;

			}

		}

		bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);

		if (!bridge_pcix_cap) {

				err = -ENODEV;

				mthca_err(mdev, "Couldn't locate HCA bridge "

					  "PCI-X capability, aborting.\n");

				goto out;

		}

	}



	/* actually hit reset */
@@ -178,6 +194,20 @@ int mthca_reset(struct mthca_dev *mdev) 
good:

	/* Now restore the PCI headers */

	if (bridge) {

		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0x8,

				 bridge_header[(bridge_pcix_cap + 0x8) / 4])) {

			err = -ENODEV;

			mthca_err(mdev, "Couldn't restore HCA bridge Upstream "

				  "split transaction control, aborting.\n");

			goto out;

		}

		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0xc,

				 bridge_header[(bridge_pcix_cap + 0xc) / 4])) {

			err = -ENODEV;

			mthca_err(mdev, "Couldn't restore HCA bridge Downstream "

				  "split transaction control, aborting.\n");

			goto out;

		}

		/*

		 * Bridge control register is at 0x3e, so we'll

		 * naturally restore it last in this loop.
@@ -203,6 +233,35 @@ int mthca_reset(struct mthca_dev *mdev) 
		}

	}



	if (hca_pcix_cap) {

		if (pci_write_config_dword(mdev->pdev, hca_pcix_cap,

				 hca_header[hca_pcix_cap / 4])) {

			err = -ENODEV;

			mthca_err(mdev, "Couldn't restore HCA PCI-X "

				  "command register, aborting.\n");

			goto out;

		}

	}



	if (hca_pcie_cap) {

		devctl = hca_header[(hca_pcie_cap + PCI_EXP_DEVCTL) / 4];

		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_DEVCTL,

					   devctl)) {

			err = -ENODEV;

			mthca_err(mdev, "Couldn't restore HCA PCI Express "

				  "Device Control register, aborting.\n");

			goto out;

		}

		linkctl = hca_header[(hca_pcie_cap + PCI_EXP_LNKCTL) / 4];

		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_LNKCTL,

					   linkctl)) {

			err = -ENODEV;

			mthca_err(mdev, "Couldn't restore HCA PCI Express "

				  "Link control register, aborting.\n");

			goto out;

		}

	}



	for (i = 0; i < 16; ++i) {

		if (i * 4 == PCI_COMMAND)

			continue;