[PATCH v2 02/24] PCI: Set error response in config access defines when ops->read() fails

From: Naveen Naidu
Date: Fri Oct 15 2021 - 10:29:46 EST


Make PCI_OP_READ and PCI_USER_READ_CONFIG set the data value with error
response (~0), when the PCI device read by a host controller fails.

This ensures that the controller drivers no longer need to fabricate
(~0) value when they detect error. It also gurantees that the error
response (~0) is always set when the controller drivers fails to read a
config register from a device.

This makes error response fabrication consistent and helps in removal of
a lot of repeated code.

Suggested-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Naveen Naidu <naveennaidu479@xxxxxxxxx>
---
drivers/pci/access.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 46935695cfb9..b3b2006ed1d2 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -42,7 +42,10 @@ int noinline pci_bus_read_config_##size \
if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
pci_lock_config(flags); \
res = bus->ops->read(bus, devfn, pos, len, &data); \
- *value = (type)data; \
+ if (res) \
+ SET_PCI_ERROR_RESPONSE(value); \
+ else \
+ *value = (type)data; \
pci_unlock_config(flags); \
return res; \
}
@@ -228,7 +231,10 @@ int pci_user_read_config_##size \
ret = dev->bus->ops->read(dev->bus, dev->devfn, \
pos, sizeof(type), &data); \
raw_spin_unlock_irq(&pci_lock); \
- *val = (type)data; \
+ if (ret) \
+ SET_PCI_ERROR_RESPONSE(val); \
+ else \
+ *val = (type)data; \
return pcibios_err_to_errno(ret); \
} \
EXPORT_SYMBOL_GPL(pci_user_read_config_##size);
--
2.25.1