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PCI/DPC: Use PCI_POSSIBLE_ERROR() to check config reads

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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.

Compile tested only.

Link: https://lore.kernel.org/r/9b0632f1f183432149f495cf12bdd5a72cc597a4.1637243717.git.naveennaidu479@gmail.com
Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Naveen Naidu 2021-11-18 19:33:29 +05:30 committed by Bjorn Helgaas
parent a3b0f10db1
commit 0242132da2
1 changed files with 2 additions and 2 deletions
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4
drivers/pci/pcie/dpc.c
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@ -79,7 +79,7 @@ static bool dpc_completed(struct pci_dev *pdev)
u16 status;
pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_STATUS, &status);
if ((status != 0xffff) && (status & PCI_EXP_DPC_STATUS_TRIGGER))
if ((!PCI_POSSIBLE_ERROR(status)) && (status & PCI_EXP_DPC_STATUS_TRIGGER))
return false;
if (test_bit(PCI_DPC_RECOVERING, &pdev->priv_flags))
@ -312,7 +312,7 @@ static irqreturn_t dpc_irq(int irq, void *context)
pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || status == (u16)(~0))
if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || PCI_POSSIBLE_ERROR(status))
return IRQ_NONE;
pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,