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And the CXL RAS Cap registers >>> reported on Protocol errors should check for AER _OSC rather than CXL >>> Memory Error Reporting Control _OSC. >>> >>> The CXL Memory Error Reporting Control _OSC specifically highlights >>> handling Memory Error Logging and Signaling Enhancements. These kinds of >>> errors are reported through a device's mailbox and can be managed >>> independently from CXL Protocol Errors. >>> >>> This change fixes handling and reporting CXL Protocol Errors and RAS >>> registers natively with native AER and FW-First CXL Memory Error >>> Reporting >>> Control. >>> >>> [1] Compute Express Link (CXL) Specification, Revision 3.1, Aug 1 2022. >>> >>> Fixes: 248529edc86f ("cxl: add RAS status unmasking for CXL") >>> Signed-off-by: Smita Koralahalli >>> >>> Reviewed-by: Robert Richter >> >> I'd be tempted to add a comment on why this returns 0 rather than an >> error.  I think that makes sense but it isn't immediately obvious from >> the local context. >> >> Otherwise LGTM >> >> Reviewed-by: Jonathan Cameron > > Echo Jonathan's comment. > > Reviewed-by: Dave Jiang Yes, and Dan is probably against returning error code. https://lore.kernel.org/all/64d1b3e78629f_5ea6e2944@dwillia2-xfh.jf.intel.com.notmuch/ But I think returning zero is required as we don't want to interfere with cxl device access when operating in native cxl memory error reporting. Returning error code will basically fail cxl_pci_probe() and thus fail to create a cxl device node. I was thinking a single line comment as: "Return zero to not block the communication with the cxl device when in native memory error reporting mode". Agree? Or anything more that needs to be added? Thanks, Smita > >> >> >>> --- >>> v2: >>>     Added fixes tag. >>>     Included what the patch fixes in commit message. >>> v3: >>>     Added "Reviewed-by" tag. >>> --- >>>   drivers/cxl/pci.c | 6 +++--- >>>   1 file changed, 3 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c >>> index 1cb1494c28fe..2323169b6e5f 100644 >>> --- a/drivers/cxl/pci.c >>> +++ b/drivers/cxl/pci.c >>> @@ -541,9 +541,9 @@ static int cxl_pci_ras_unmask(struct pci_dev *pdev) >>>           return 0; >>>       } >>> -    /* BIOS has CXL error control */ >>> -    if (!host_bridge->native_cxl_error) >>> -        return -ENXIO; >>> +    /* BIOS has PCIe AER error control */ >>> +    if (!host_bridge->native_aer) >>> +        return 0; >>>       rc = pcie_capability_read_word(pdev, PCI_EXP_DEVCTL, &cap); >>>       if (rc) >>