myri10ge: Mask PCI Surprise Link Down Events

A SRAM parity error can cause a surprise link down.  Since We can
recover from SRAM parity errors, mask PCI surprise down events.

Signed-off-by: Jon Mason <mason@myri.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/net/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index a8ae641d0bd1..0f0f83d50ddc 100644
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -3327,6 +3327,26 @@ static void myri10ge_select_firmware(struct myri10ge_priv *mgp)
                          mgp->fw_name);
 }
 
+static void myri10ge_mask_surprise_down(struct pci_dev *pdev)
+{
+        struct pci_dev *bridge = pdev->bus->self;
+        int cap;
+        u32 mask;
+
+        if (bridge == NULL)
+                return;
+
+        cap = pci_find_ext_capability(bridge, PCI_EXT_CAP_ID_ERR);
+        if (cap) {
+                /* a sram parity error can cause a surprise link
+                 * down; since we expect and can recover from sram
+                 * parity errors, mask surprise link down events */
+                pci_read_config_dword(bridge, cap + PCI_ERR_UNCOR_MASK, &mask);
+                mask |= 0x20;
+                pci_write_config_dword(bridge, cap + PCI_ERR_UNCOR_MASK, mask);
+        }
+}
+
 #ifdef CONFIG_PM
 static int myri10ge_suspend(struct pci_dev *pdev, pm_message_t state)
 {
@@ -3845,6 +3865,7 @@ static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
                 goto abort_with_enabled;
         }
 
+        myri10ge_mask_surprise_down(pdev);
         pci_set_master(pdev);
         dac_enabled = 1;
         status = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));