1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index cf57fe79450a..b50386dc72e0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -156,6 +156,8 @@ static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar)
         return flags;
 }
 
+#define PCI_COMMAND_DECODE_ENABLE       (PCI_COMMAND_MEMORY | PCI_COMMAND_IO)
+
 /**
  * pci_read_base - read a PCI BAR
  * @dev: the PCI device
@@ -178,8 +180,10 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
         /* No printks while decoding is disabled! */
         if (!dev->mmio_always_on) {
                 pci_read_config_word(dev, PCI_COMMAND, &orig_cmd);
-                pci_write_config_word(dev, PCI_COMMAND,
-                        orig_cmd & ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO));
+                if (orig_cmd & PCI_COMMAND_DECODE_ENABLE) {
+                        pci_write_config_word(dev, PCI_COMMAND,
+                                orig_cmd & ~PCI_COMMAND_DECODE_ENABLE);
+                }
         }
 
         res->name = pci_name(dev);
@@ -293,7 +297,8 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 fail:
         res->flags = 0;
 out:
-        if (!dev->mmio_always_on)
+        if (!dev->mmio_always_on &&
+            (orig_cmd & PCI_COMMAND_DECODE_ENABLE))
                 pci_write_config_word(dev, PCI_COMMAND, orig_cmd);
 
         if (bar_too_big)