On Fri, Oct 15, 2021 at 08:08:45PM +0530, Naveen Naidu wrote:

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.

The host controller drivers sets the error response values (~0) and
returns an error when faulty hardware read occurs. But the error
response value (~0) is already being set in PCI_OP_READ and
PCI_USER_READ_CONFIG whenever a read by host controller driver fails.

Thus, it's no longer necessary for the host controller drivers to
fabricate any error response.

This helps unify PCI error response checking and make error check
consistent and easier to find.

Signed-off-by: Naveen Naidu <redacted>
---
 drivers/pci/access.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

Reviewed-by: Rob Herring <robh@kernel.org>
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