[PATCH] sky2: pci config space checking

There were bugs in mmconfig access to PCI space, up to and
include 2.6.16-rc1. These prevented the sky2 driver from being
able to clear PCI express errors.

This patch makes the driver check (during probe), for errors
in PCI config access and fail.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 22 insertions, 9 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index c236c5984743..e04c4f40e0bb 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -2142,7 +2142,7 @@ static int sky2_reset(struct sky2_hw *hw)
 {
         u16 status;
         u8 t8, pmd_type;
-        int i;
+        int i, err;
 
         sky2_write8(hw, B0_CTST, CS_RST_CLR);
 
@@ -2164,19 +2164,24 @@ static int sky2_reset(struct sky2_hw *hw)
         sky2_write8(hw, B0_CTST, CS_RST_CLR);
 
         /* clear PCI errors, if any */
-        pci_read_config_word(hw->pdev, PCI_STATUS, &status);
+        err = pci_read_config_word(hw->pdev, PCI_STATUS, &status);
+        if (err)
+                goto pci_err;
+
         sky2_write8(hw, B2_TST_CTRL1, TST_CFG_WRITE_ON);
-        pci_write_config_word(hw->pdev, PCI_STATUS,
-                              status | PCI_STATUS_ERROR_BITS);
+        err = pci_write_config_word(hw->pdev, PCI_STATUS,
+                                    status | PCI_STATUS_ERROR_BITS);
+        if (err)
+                goto pci_err;
 
         sky2_write8(hw, B0_CTST, CS_MRST_CLR);
 
         /* clear any PEX errors */
-        if (is_pciex(hw)) {
-                u16 lstat;
-                pci_write_config_dword(hw->pdev, PEX_UNC_ERR_STAT,
-                                       0xffffffffUL);
-                pci_read_config_word(hw->pdev, PEX_LNK_STAT, &lstat);
+        if (pci_find_capability(hw->pdev, PCI_CAP_ID_EXP)) {
+                err = pci_write_config_dword(hw->pdev, PEX_UNC_ERR_STAT,
+                                                 0xffffffffUL);
+                if (err)
+                        goto pci_err;
         }
 
         pmd_type = sky2_read8(hw, B2_PMD_TYP);
@@ -2288,6 +2293,14 @@ static int sky2_reset(struct sky2_hw *hw)
         sky2_write8(hw, STAT_ISR_TIMER_CTRL, TIM_START);
 
         return 0;
+
+pci_err:
+        /* This is to catch a BIOS bug workaround where
+         * mmconfig table doesn't have other buses.
+         */
+        printk(KERN_ERR PFX "%s: can't access PCI config space\n",
+               pci_name(hw->pdev));
+        return err;
 }
 
 static u32 sky2_supported_modes(const struct sky2_hw *hw)