RE: [PATCH v3 6/9] cxl/pci: Do not ignore PCI config read errors in match_add_dports()

From: Dan Williams
Date: Wed Nov 16 2022 - 14:36:59 EST


Robert Richter wrote:
> The link capabilities of a PCI device are read when enumerating its
> dports. This is done by reading the PCI config space. If that fails
> port enumeration ignores that error. However, reading the PCI config
> space should reliably work.
>
> To reduce some complexity to the code flow when factoring out parts of
> the code in match_add_dports() for later reuse, change this to throw
> an error.
>
> Signed-off-by: Robert Richter <rrichter@xxxxxxx>
> ---
> drivers/cxl/core/pci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index 0dbbe8d39b07..8271b8abde7a 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -47,7 +47,7 @@ static int match_add_dports(struct pci_dev *pdev, void *data)

match_add_dports() never comes into play in the RCH topology case. There
are no switch ports to handle and CXL host-bridges are only ever dports
in the RCH case.

I will post the cxl_test enabling for an RCH topology so we can compare
notes there.