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authorDean Nelson <dnelson@redhat.com>2010-03-10 06:26:55 +0300
committerJesse Barnes <jbarnes@virtuousgeek.org>2010-03-19 22:41:48 +0300
commit7c9e2b1c4784c6e574f69dbd904b2822f2e04d6e (patch)
tree4f11b13961671d83128866aa456688c7e437f243 /drivers/pci
parentbdc2bda7c4dd253026cc1fce45fc939304749029 (diff)
downloadlinux-7c9e2b1c4784c6e574f69dbd904b2822f2e04d6e.tar.xz
PCI: cleanup error return for pcix get and set mmrbc functions
pcix_get_mmrbc() returns the maximum memory read byte count (mmrbc), if successful, or an appropriate error value, if not. Distinguishing errors from correct values and understanding the meaning of an error can be somewhat confusing in that: correct values: 512, 1024, 2048, 4096 errors: -EINVAL -22 PCIBIOS_FUNC_NOT_SUPPORTED 0x81 PCIBIOS_BAD_VENDOR_ID 0x83 PCIBIOS_DEVICE_NOT_FOUND 0x86 PCIBIOS_BAD_REGISTER_NUMBER 0x87 PCIBIOS_SET_FAILED 0x88 PCIBIOS_BUFFER_TOO_SMALL 0x89 The PCIBIOS_ errors are returned from the PCI functions generated by the PCI_OP_READ() and PCI_OP_WRITE() macros. In a similar manner, pcix_set_mmrbc() also returns the PCIBIOS_ error values returned from pci_read_config_[word|dword]() and pci_write_config_word(). Following pcix_get_max_mmrbc()'s example, the following patch simply returns -EINVAL for all PCIBIOS_ errors encountered by pcix_get_mmrbc(), and -EINVAL or -EIO for those encountered by pcix_set_mmrbc(). This simplification was chosen in light of the fact that none of the current callers of these functions are interested in the specific type of error encountered. In the future, should this change, one could simply create a function that maps each PCIBIOS_ error to a corresponding unique errno value, which could be called by pcix_get_max_mmrbc(), pcix_get_mmrbc(), and pcix_set_mmrbc(). Additionally, this patch eliminates some unnecessary variables. Cc: stable@kernel.org Signed-off-by: Dean Nelson <dnelson@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/pci.c36
1 files changed, 16 insertions, 20 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 5c80b59c5931..1531f3a49879 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2576,15 +2576,14 @@ EXPORT_SYMBOL_GPL(pci_reset_function);
*/
int pcix_get_max_mmrbc(struct pci_dev *dev)
{
- int err, cap;
+ int cap;
u32 stat;
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!cap)
return -EINVAL;
- err = pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat);
- if (err)
+ if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
return -EINVAL;
return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
@@ -2600,18 +2599,17 @@ EXPORT_SYMBOL(pcix_get_max_mmrbc);
*/
int pcix_get_mmrbc(struct pci_dev *dev)
{
- int ret, cap;
+ int cap;
u16 cmd;
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!cap)
return -EINVAL;
- ret = pci_read_config_word(dev, cap + PCI_X_CMD, &cmd);
- if (!ret)
- ret = 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
+ if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
+ return -EINVAL;
- return ret;
+ return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
}
EXPORT_SYMBOL(pcix_get_mmrbc);
@@ -2626,29 +2624,27 @@ EXPORT_SYMBOL(pcix_get_mmrbc);
*/
int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
{
- int cap, err = -EINVAL;
+ int cap;
u32 stat, v, o;
u16 cmd;
if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
- goto out;
+ return -EINVAL;
v = ffs(mmrbc) - 10;
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!cap)
- goto out;
+ return -EINVAL;
- err = pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat);
- if (err)
- goto out;
+ if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
+ return -EINVAL;
if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
return -E2BIG;
- err = pci_read_config_word(dev, cap + PCI_X_CMD, &cmd);
- if (err)
- goto out;
+ if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
+ return -EINVAL;
o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
if (o != v) {
@@ -2658,10 +2654,10 @@ int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
cmd &= ~PCI_X_CMD_MAX_READ;
cmd |= v << 2;
- err = pci_write_config_word(dev, cap + PCI_X_CMD, cmd);
+ if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
+ return -EIO;
}
-out:
- return err;
+ return 0;
}
EXPORT_SYMBOL(pcix_set_mmrbc);