Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

[deliverable/linux.git] / drivers / pci / pci-sysfs.c

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 76ef7914c9aa22c03631579c3990e0cc228f5051..92b6d9ab00e498ac02fdd08ead2d4f3bfc76d207 100644 (file)
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -250,46 +250,45 @@ static ssize_t msi_bus_show(struct device *dev, struct device_attribute *attr,
                            char *buf)
 {
        struct pci_dev *pdev = to_pci_dev(dev);
+       struct pci_bus *subordinate = pdev->subordinate;
 
-       if (!pdev->subordinate)
-               return 0;
-
-       return sprintf(buf, "%u\n",
-                      !(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI));
+       return sprintf(buf, "%u\n", subordinate ?
+                      !(subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI)
+                          : !pdev->no_msi);
 }
 
 static ssize_t msi_bus_store(struct device *dev, struct device_attribute *attr,
                             const char *buf, size_t count)
 {
        struct pci_dev *pdev = to_pci_dev(dev);
+       struct pci_bus *subordinate = pdev->subordinate;
        unsigned long val;
 
        if (kstrtoul(buf, 0, &val) < 0)
                return -EINVAL;
 
-       /*
-        * Bad things may happen if the no_msi flag is changed
-        * while drivers are loaded.
-        */
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
 
        /*
-        * Maybe devices without subordinate buses shouldn't have this
-        * attribute in the first place?
+        * "no_msi" and "bus_flags" only affect what happens when a driver
+        * requests MSI or MSI-X.  They don't affect any drivers that have
+        * already requested MSI or MSI-X.
         */
-       if (!pdev->subordinate)
+       if (!subordinate) {
+               pdev->no_msi = !val;
+               dev_info(&pdev->dev, "MSI/MSI-X %s for future drivers\n",
+                        val ? "allowed" : "disallowed");
                return count;
-
-       /* Is the flag going to change, or keep the value it already had? */
-       if (!(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI) ^
-           !!val) {
-               pdev->subordinate->bus_flags ^= PCI_BUS_FLAGS_NO_MSI;
-
-               dev_warn(&pdev->dev, "forced subordinate bus to%s support MSI, bad things could happen\n",
-                        val ? "" : " not");
        }
 
+       if (val)
+               subordinate->bus_flags &= ~PCI_BUS_FLAGS_NO_MSI;
+       else
+               subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
+
+       dev_info(&subordinate->dev, "MSI/MSI-X %s for future drivers of devices on this bus\n",
+                val ? "allowed" : "disallowed");
        return count;
 }
 static DEVICE_ATTR_RW(msi_bus);