Re: [PATCH v15 10/16] PCI/CXL: Add CXL Device Reset sequencing

[Srirangan Madhavan <smadhavan@nvidia.com>]

On 10/27/26 8:01 PM, Li Ming wrote:
>> +
>> +     rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL2, 
>> &ctrl2);
>> +     if (rc)
>> +             return pcibios_err_to_errno(rc);
>> +     if (PCI_POSSIBLE_ERROR(ctrl2))
>> +             return -ENODEV;
> 
> I think this PCI_POSSIBLE_ERROR() checking is not needed, in
> pci_bus_read_config_word() marco, if bus->ops->read() returns a error,
> then the function will use PCI_SET_ERROR_RESPONSE() then returning the
> errno. That means that we can always get an error as return value of
> pci_read_config_word() while ctrl2 is an error response.

I kept the PCI_POSSIBLE_ERROR() checks in v16 because I believe 
configuration read can return success with an all-ones value. For 
example, pci_generic_config_read() returns success after readw(), even 
if the value read is 0xffff.
Please let me know if that assumption is incorrect.
-- 
Regards,
Srirangan