sky2: handle advanced error recovery config issues

The PCI AER support may not work for a couple of reasons.
It may not be configured into the kernel or there may be a BIOS
bug that prevents MMCONFIG from working.  If MMCONFIG doesn't work
then the PCI registers that control AER will not be accessible via
pci_read_config functions; luckly there is another window to access
PCI space in the device, so use that.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 30 insertions, 7 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 76038bbeb50e..a6ccd11574d0 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -2435,13 +2435,26 @@ static void sky2_hw_intr(struct sky2_hw *hw)
 
         if (status & Y2_IS_PCI_EXP) {
                 /* PCI-Express uncorrectable Error occurred */
-                int pos = pci_find_aer_capability(hw->pdev);
+                int aer = pci_find_aer_capability(hw->pdev);
                 u32 err;
 
-                pci_read_config_dword(pdev, pos + PCI_ERR_UNCOR_STATUS, &err);
+                if (aer) {
+                        pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS,
+                                              &err);
+                        pci_cleanup_aer_uncorrect_error_status(pdev);
+                } else {
+                        /* Either AER not configured, or not working
+                         * because of bad MMCONFIG, so just do recover
+                         * manually.
+                         */
+                        err = sky2_read32(hw, Y2_CFG_AER + PCI_ERR_UNCOR_STATUS);
+                        sky2_write32(hw, Y2_CFG_AER + PCI_ERR_UNCOR_STATUS,
+                                     0xfffffffful);
+                }
+
                 if (net_ratelimit())
                         dev_err(&pdev->dev, "PCI Express error (0x%x)\n", err);
-                pci_cleanup_aer_uncorrect_error_status(pdev);
+
         }
 
         if (status & Y2_HWE_L1_MASK)
@@ -2799,9 +2812,18 @@ static void sky2_reset(struct sky2_hw *hw)
 
         cap = pci_find_capability(pdev, PCI_CAP_ID_EXP);
         if (cap) {
-                /* Check for advanced error reporting */
-                pci_cleanup_aer_uncorrect_error_status(pdev);
-                pci_cleanup_aer_correct_error_status(pdev);
+                if (pci_find_aer_capability(pdev)) {
+                        /* Check for advanced error reporting */
+                        pci_cleanup_aer_uncorrect_error_status(pdev);
+                        pci_cleanup_aer_correct_error_status(pdev);
+                } else {
+                        dev_warn(&pdev->dev,
+                                "PCI Express Advanced Error Reporting"
+                                " not configured or MMCONFIG problem?\n");
+
+                        sky2_write32(hw, Y2_CFG_AER + PCI_ERR_UNCOR_STATUS,
+                                     0xfffffffful);
+                }
 
                 /* If error bit is stuck on ignore it */
                 if (sky2_read32(hw, B0_HWE_ISRC) & Y2_IS_PCI_EXP)
diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h
index 49ee264064ab..69525fd7908d 100644
--- a/drivers/net/sky2.h
+++ b/drivers/net/sky2.h
@@ -247,7 +247,8 @@ enum csr_regs {
         B3_PA_CTRL      = 0x01f0,
         B3_PA_TEST      = 0x01f2,
 
-        Y2_CFG_SPC      = 0x1c00,
+        Y2_CFG_SPC      = 0x1c00,       /* PCI config space region */
+        Y2_CFG_AER      = 0x1d00,       /* PCI Advanced Error Report region */
 };
 
 /*      B0_CTST                 16 bit  Control/Status register */