PCI: handle positive error codes
Greg Thelen [Sun, 17 Apr 2011 15:20:32 +0000 (08:20 -0700)]
Callers expect pci_user_{read,write}_config_*() to indicate errors by
returning negative values.  Prior to this change, the indicated routines
could return positive error codes (e.g. PCIBIOS_BAD_REGISTER_NUMBER)
which callers would mistakenly interpret as success.

This change converts any non-zero return from the mentioned routines
into unambiguous negative value return codes.

Signed-off-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/access.c

index 0c1f20f..fdaa42a 100644 (file)
@@ -143,33 +143,41 @@ static noinline void pci_wait_ucfg(struct pci_dev *dev)
        __remove_wait_queue(&pci_ucfg_wait, &wait);
 }
 
+/* Returns 0 on success, negative values indicate error. */
 #define PCI_USER_READ_CONFIG(size,type)                                        \
 int pci_user_read_config_##size                                                \
        (struct pci_dev *dev, int pos, type *val)                       \
 {                                                                      \
        int ret = 0;                                                    \
        u32 data = -1;                                                  \
-       if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;       \
+       if (PCI_##size##_BAD)                                           \
+               return -EINVAL;                                         \
        raw_spin_lock_irq(&pci_lock);                           \
        if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev);       \
        ret = dev->bus->ops->read(dev->bus, dev->devfn,                 \
                                        pos, sizeof(type), &data);      \
        raw_spin_unlock_irq(&pci_lock);                         \
        *val = (type)data;                                              \
+       if (ret > 0)                                                    \
+               ret = -EINVAL;                                          \
        return ret;                                                     \
 }
 
+/* Returns 0 on success, negative values indicate error. */
 #define PCI_USER_WRITE_CONFIG(size,type)                               \
 int pci_user_write_config_##size                                       \
        (struct pci_dev *dev, int pos, type val)                        \
 {                                                                      \
        int ret = -EIO;                                                 \
-       if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;       \
+       if (PCI_##size##_BAD)                                           \
+               return -EINVAL;                                         \
        raw_spin_lock_irq(&pci_lock);                           \
        if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev);       \
        ret = dev->bus->ops->write(dev->bus, dev->devfn,                \
                                        pos, sizeof(type), val);        \
        raw_spin_unlock_irq(&pci_lock);                         \
+       if (ret > 0)                                                    \
+               ret = -EINVAL;                                          \
        return ret;                                                     \
 }
 
@@ -197,6 +205,8 @@ struct pci_vpd_pci22 {
  * This code has to spin since there is no other notification from the PCI
  * hardware. Since the VPD is often implemented by serial attachment to an
  * EEPROM, it may take many milliseconds to complete.
+ *
+ * Returns 0 on success, negative values indicate error.
  */
 static int pci_vpd_pci22_wait(struct pci_dev *dev)
 {
@@ -212,7 +222,7 @@ static int pci_vpd_pci22_wait(struct pci_dev *dev)
        for (;;) {
                ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR,
                                                &status);
-               if (ret)
+               if (ret < 0)
                        return ret;
 
                if ((status & PCI_VPD_ADDR_F) == vpd->flag) {