Messages in this thread | | | Date | Mon, 11 Oct 2021 21:47:40 +0200 | From | Lukas Wunner <> | Subject | Re: [PATCH 16/22] PCI: pciehp: Use RESPONSE_IS_PCI_ERROR() to check read from hardware |
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On Mon, Oct 11, 2021 at 11:37:33PM +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. > > Use RESPONSE_IS_PCI_ERROR() to check the response we get when we read > data from hardware.
Actually what happens is that PCI read transactions *time out*, so the host controller fabricates a response.
By contrast, a PCI *error* usually denotes an Uncorrectable or Correctable Error as specified in section 6.2.2 of the PCIe Base Spec.
Thus something like RESPONSE_IS_PCI_TIMEOUT() or IS_PCI_TIMEOUT() would probably be more appropriate. I'll leave the exact bikeshed color for others to decide. :-)
> Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com> > --- > drivers/pci/hotplug/pciehp_hpc.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-)
Acked-by: Lukas Wunner <lukas@wunner.de>
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