PCI: check for pci bar restore completion and retry

On some OEM systems, pci_restore_state() is called while FLR has not yet
completed.  As a result, PCI BAR register restore is not successful.  This fix
reads back the restored value and compares it with saved value and re-tries 10
times before giving up.

Signed-off-by: Jean Guyader <jean.guyader@eu.citrix.com>
Signed-off-by: Eric Chanudet <eric.chanudet@citrix.com>
Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 053670e09e2b93bafa15e3662c8672fdebd8ef34..9c89447e7b212cbe50613913adced9c74537c3a5 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -959,6 +959,7 @@ void pci_restore_state(struct pci_dev *dev)
 {
        int i;
        u32 val;
+       int tries;
 
        if (!dev->state_saved)
                return;
@@ -973,12 +974,16 @@ void pci_restore_state(struct pci_dev *dev)
         */
        for (i = 15; i >= 0; i--) {
                pci_read_config_dword(dev, i * 4, &val);
-               if (val != dev->saved_config_space[i]) {
+               tries = 10;             
+               while (tries && val != dev->saved_config_space[i]) {
                        dev_dbg(&dev->dev, "restoring config "
                                "space at offset %#x (was %#x, writing %#x)\n",
                                i, val, (int)dev->saved_config_space[i]);
                        pci_write_config_dword(dev,i * 4,
                                dev->saved_config_space[i]);
+                       pci_read_config_dword(dev, i * 4, &val);
+                       mdelay(10);
+                       tries--;
                }
        }
        pci_restore_pcix_state(dev);