PCI: Set error response data when config read fails

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When a PCI config read fails, most PCI host bridges fabricate ~0 data to
complete the CPU read.  But some host bridges do not; their drivers may
only return an error from the pci_ops.read() method.

In PCI_OP_READ() and PCI_USER_READ_CONFIG(), use PCI_SET_ERROR_RESPONSE()
to set the data value to indicate an error when pci_ops.read() fails.

This means the host bridge driver no longer needs to fabricate error data
when they detect errors.

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

Suggested-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/4188fc5465631ce0d472d1423de3d9fb2f09b8ff.1637243717.git.naveennaidu479@gmail.com
Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Pali Rohár <pali@kernel.org>

...

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Naveen Naidu 2021-11-18 19:33:12 +05:30 • committed by Bjorn Helgaas

parent 57bdeef471

commit f4f7eb43c5

1 changed files with 8 additions and 2 deletions

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drivers/pci/access.c

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