[patch 02/45] IB/mthca: restore missing PCI registers after reset

Greg KH
2006-07-17T16:34:09Z

[-- Attachment #1: ib-mthca-restore-missing-pci-registers-after-reset.patch --]
[-- Type: text/plain, Size: 3584 bytes --]

-stable review patch. If anyone has any objections, please let us know.

------------------
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: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/infiniband/hw/mthca/mthca_reset.c | 59 ++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)

--- linux-2.6.17.2.orig/drivers/infiniband/hw/mthca/mthca_reset.c
+++ linux-2.6.17.2/drivers/infiniband/hw/mthca/mthca_reset.c
@@ -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 @@ good:
}
}

+ 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;

--