An MMIO read from a PCI device that doesn't exist or doesn't respond
causes a PCI error. There's no real data to return to satisfy the
CPU read, so most hardware fabricates ~0 data.
Use SET_PCI_ERROR_RESPONSE() to set the error response and
RESPONSE_IS_PCI_ERROR() to check the error response during hardware
read.
These definitions make error checks consistent and easier to find.
Signed-off-by: Naveen Naidu <naveennaidu479@xxxxxxxxx>
---
drivers/pci/access.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index b3b2006ed1d2..03712866c818 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -417,10 +417,10 @@ int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val)
ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val);
/*
* Reset *val to 0 if pci_read_config_word() fails, it may
- * have been written as 0xFFFF if hardware error happens
- * during pci_read_config_word().
+ * have been written as 0xFFFF (PCI_ERROR_RESPONSE) if hardware error
+ * happens during pci_read_config_word().
*/
- if (ret)
+ if (RESPONSE_IS_PCI_ERROR(val))
*val = 0;
return ret;
}
@@ -452,10 +452,10 @@ int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val)
ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val);
/*
* Reset *val to 0 if pci_read_config_dword() fails, it may
- * have been written as 0xFFFFFFFF if hardware error happens
- * during pci_read_config_dword().
+ * have been written as 0xFFFFFFFF (PCI_ERROR_RESPONSE) if hardware
+ * error happens during pci_read_config_dword().
*/
- if (ret)
+ if (RESPONSE_IS_PCI_ERROR(val))
*val = 0;
return ret;
}
@@ -529,7 +529,7 @@ EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);
int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)
{
if (pci_dev_is_disconnected(dev)) {
- *val = ~0;
+ SET_PCI_ERROR_RESPONSE(val);
return PCIBIOS_DEVICE_NOT_FOUND;
}
return pci_bus_read_config_byte(dev->bus, dev->devfn, where, val);
@@ -539,7 +539,7 @@ EXPORT_SYMBOL(pci_read_config_byte);
int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val)
{
if (pci_dev_is_disconnected(dev)) {
- *val = ~0;
+ SET_PCI_ERROR_RESPONSE(val);
return PCIBIOS_DEVICE_NOT_FOUND;
}
return pci_bus_read_config_word(dev->bus, dev->devfn, where, val);
@@ -550,7 +550,7 @@ int pci_read_config_dword(const struct pci_dev *dev, int where,
u32 *val)
{
if (pci_dev_is_disconnected(dev)) {
- *val = ~0;
+ SET_PCI_ERROR_RESPONSE(val);
return PCIBIOS_DEVICE_NOT_FOUND;
}
return pci_bus_read_config_dword(dev->bus, dev->devfn, where, val);
--
2.25.1
