2011-04-17 15:20:47

by Greg Thelen

[permalink] [raw]
Subject: [PATCH] PCI: handle positive error codes

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 <[email protected]>
---
drivers/pci/access.c | 16 +++++++++++++---
1 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 531bc69..502610b 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -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) {
--
1.7.3.1