Re: [RFC PATCH v2 07/32] PCI/portdrv: use PCIe capabilities access functions to simplify implementation

[Jiang Liu <jiang.liu@huawei.com>]

>> diff --git a/drivers/pci/pcie/portdrv_core.c
>> b/drivers/pci/pcie/portdrv_core.c
>> index bf320a9..37bff83 100644
>> --- a/drivers/pci/pcie/portdrv_core.c
>> +++ b/drivers/pci/pcie/portdrv_core.c
>> @@ -76,7 +76,6 @@ static int pcie_port_enable_msix(struct pci_dev *dev,
>> int *vectors, int mask)
>>  	struct msix_entry *msix_entries;
>>  	int idx[PCIE_PORT_DEVICE_MAXSERVICES];
>>  	int nr_entries, status, pos, i, nvec;
>> -	u16 reg16;
>>  	u32 reg32;
>>
>>  	nr_entries = pci_msix_table_size(dev);
>> @@ -120,9 +119,7 @@ static int pcie_port_enable_msix(struct pci_dev *dev,
>> int *vectors, int mask)
>>  		 * the value in this field indicates which MSI-X Table entry
>> is
>>  		 * used to generate the interrupt message."
>>  		 */
>> -		pos = pci_pcie_cap(dev);
>> -		pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &reg16);
>> -		entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
>> +		entry = (dev->pcie_flags_reg & PCI_EXP_FLAGS_IRQ) >> 9;
>>  		if (entry >= nr_entries)
>>  			goto Error;
> 
> I think we need to use pci_read_config_word() for MSI setup.
> 
> "Interrupt Message Number" in the PCIe capability register can vary depending
> on whether MSI or MSI-x is enabled. Please see PCIe spec for details.
> 
> Could you double-check that?
> 
> Regards,
> Kenji Kaneshige
Good catch, will revert this change.
Thanks!
Gerry