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[v4,10/25] PCI: kirin: Remove redundant error fabrication when device read fails

Message ID f87e22bc09a471d2cf15ad05dfd6432f57739aed.1637243717.git.naveennaidu479@gmail.com (mailing list archive)
State Accepted
Headers show
Series Unify PCI error response checking | expand

Commit Message

Naveen Naidu Nov. 18, 2021, 2:03 p.m. UTC 
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 <naveennaidu479@gmail.com>
---
 drivers/pci/controller/dwc/pcie-kirin.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-kirin.c b/drivers/pci/controller/dwc/pcie-kirin.c
index 095afbccf9c1..e6dcac79c02a 100644
--- a/drivers/pci/controller/dwc/pcie-kirin.c
+++ b/drivers/pci/controller/dwc/pcie-kirin.c
@@ -530,10 +530,8 @@  static int kirin_pcie_rd_own_conf(struct pci_bus *bus, unsigned int devfn,
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(bus->sysdata);
 
-	if (PCI_SLOT(devfn)) {
-		*val = ~0;
+	if (PCI_SLOT(devfn))
 		return PCIBIOS_DEVICE_NOT_FOUND;
-	}
 
 	*val = dw_pcie_read_dbi(pci, where, size);
 	return PCIBIOS_SUCCESSFUL;