Merge tag 'pci-v4.14-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fix from Bjorn Helgaas:
 "Revert an attempt to fix a race while enabling upstream bridges
  because it broke iwlwifi firmware loading"

* tag 'pci-v4.14-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  Revert "PCI: Avoid race while enabling upstream bridges"

1 files changed, 2 insertions, 11 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b0002daa50f3..6078dfc11b11 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -52,7 +52,6 @@ static void pci_pme_list_scan(struct work_struct *work);
 static LIST_HEAD(pci_pme_list);
 static DEFINE_MUTEX(pci_pme_list_mutex);
 static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
-static DEFINE_MUTEX(pci_bridge_mutex);
 
 struct pci_pme_device {
         struct list_head list;
@@ -1351,16 +1350,10 @@ static void pci_enable_bridge(struct pci_dev *dev)
         if (bridge)
                 pci_enable_bridge(bridge);
 
-        /*
-         * Hold pci_bridge_mutex to prevent a race when enabling two
-         * devices below the bridge simultaneously.  The race may cause a
-         * PCI_COMMAND_MEMORY update to be lost (see changelog).
-         */
-        mutex_lock(&pci_bridge_mutex);
         if (pci_is_enabled(dev)) {
                 if (!dev->is_busmaster)
                         pci_set_master(dev);
-                goto end;
+                return;
         }
 
         retval = pci_enable_device(dev);
@@ -1368,8 +1361,6 @@ static void pci_enable_bridge(struct pci_dev *dev)
                 dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n",
                         retval);
         pci_set_master(dev);
-end:
-        mutex_unlock(&pci_bridge_mutex);
 }
 
 static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
@@ -1394,7 +1385,7 @@ static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
                 return 0;               /* already enabled */
 
         bridge = pci_upstream_bridge(dev);
-        if (bridge && !pci_is_enabled(bridge))
+        if (bridge)
                 pci_enable_bridge(bridge);
 
         /* only skip sriov related */