From 242f288e82a34b4c10f87e121b0755056675e55d Mon Sep 17 00:00:00 2001
From: Naveen Naidu <naveennaidu479@gmail.com>
Date: Thu, 18 Nov 2021 19:33:27 +0530
Subject: [PATCH] PCI: vmd: Use PCI_POSSIBLE_ERROR() to check config reads
When config pci_ops.read() can detect failed PCI transactions, the data
returned to the CPU is PCI_ERROR_RESPONSE (~0 or 0xffffffff).
Obviously a successful PCI config read may *also* return that data if a
config register happens to contain ~0, so it doesn't definitively indicate
an error unless we know the register cannot contain ~0.
Use PCI_POSSIBLE_ERROR() to check the response we get when we read data
from hardware. This unifies PCI error response checking and makes error
checks consistent and easier to find.
Link: https://lore.kernel.org/r/ed01cad87a2e35f3865275b5fb34290817a1ebf8.1637243717.git.naveennaidu479@gmail.com
Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Derrick <jonathan.derrick@linux.dev>
---
drivers/pci/controller/vmd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index a45e8e59d3d48..515d05605204a 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -541,7 +541,7 @@ static int vmd_get_phys_offsets(struct vmd_dev *vmd, bool native_hint,
int ret;
ret = pci_read_config_dword(dev, PCI_REG_VMLOCK, &vmlock);
- if (ret || vmlock == ~0)
+ if (ret || PCI_POSSIBLE_ERROR(vmlock))
return -ENODEV;
if (MB2_SHADOW_EN(vmlock)) {
--
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