Re: [PATCH 1/3] PCI: move PCI_FIND_CAP_TTL to pci.h and use it in quirks

[Wei Yang <weiyang@linux.vnet.ibm.com>]

On Wed, Oct 22, 2014 at 05:18:30PM -0600, Bjorn Helgaas wrote:
>[+cc Yinghai]
>
>On Tue, Oct 14, 2014 at 02:47:30PM +0800, Wei Yang wrote:
>> In some quirks, it tries to search a pci cap and use a ttl value to avoid
>> infinite loop. While the value is hard coded to 48, which is the same as marco
>> PCI_FIND_CAP_TTL.
>> 
>> This patch moves the definition of PCI_FIND_CAP_TTL to pci.h and replace the
>> hard coded value with it.
>
>This seems reasonable (though I added Yinghai in case he knows of any
>reason why HT capabilities should be different from plain PCI capabilities
>in this respect).
>
>But I'd prefer to have the definition in drivers/pci/pci.h rather than in
>include/linux/pci.h, because both users already include drivers/pci/pci.h,
>and it is less visible.

Got it.

>
>Bjorn
>
>> 
>> Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
>> ---
>>  drivers/pci/pci.c    |    1 -
>>  drivers/pci/quirks.c |    8 ++++----
>>  include/linux/pci.h  |    2 ++
>>  3 files changed, 6 insertions(+), 5 deletions(-)
>> 
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index 2c9ac70..76b002b1 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -137,7 +137,6 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
>>  EXPORT_SYMBOL_GPL(pci_ioremap_bar);
>>  #endif
>>  
>> -#define PCI_FIND_CAP_TTL	48
>>  
>>  static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
>>  				   u8 pos, int cap, int *ttl)
>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>> index 80c2d01..a5f46b8 100644
>> --- a/drivers/pci/quirks.c
>> +++ b/drivers/pci/quirks.c
>> @@ -2176,7 +2176,7 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, 0x9601, quirk_amd_780_apc_msi);
>>   * return 1 if a HT MSI capability is found and enabled */
>>  static int msi_ht_cap_enabled(struct pci_dev *dev)
>>  {
>> -	int pos, ttl = 48;
>> +	int pos, ttl = PCI_FIND_CAP_TTL;
>>  
>>  	pos = pci_find_ht_capability(dev, HT_CAPTYPE_MSI_MAPPING);
>>  	while (pos && ttl--) {
>> @@ -2235,7 +2235,7 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_CK804_PCIE,
>>  /* Force enable MSI mapping capability on HT bridges */
>>  static void ht_enable_msi_mapping(struct pci_dev *dev)
>>  {
>> -	int pos, ttl = 48;
>> +	int pos, ttl = PCI_FIND_CAP_TTL;
>>  
>>  	pos = pci_find_ht_capability(dev, HT_CAPTYPE_MSI_MAPPING);
>>  	while (pos && ttl--) {
>> @@ -2314,7 +2314,7 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA,
>>  
>>  static int ht_check_msi_mapping(struct pci_dev *dev)
>>  {
>> -	int pos, ttl = 48;
>> +	int pos, ttl = PCI_FIND_CAP_TTL;
>>  	int found = 0;
>>  
>>  	/* check if there is HT MSI cap or enabled on this device */
>> @@ -2439,7 +2439,7 @@ out:
>>  
>>  static void ht_disable_msi_mapping(struct pci_dev *dev)
>>  {
>> -	int pos, ttl = 48;
>> +	int pos, ttl = PCI_FIND_CAP_TTL;
>>  
>>  	pos = pci_find_ht_capability(dev, HT_CAPTYPE_MSI_MAPPING);
>>  	while (pos && ttl--) {
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index 96453f9..b27b79e 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -33,6 +33,8 @@
>>  
>>  #include <linux/pci_ids.h>
>>  
>> +#define PCI_FIND_CAP_TTL	48
>> +
>>  /*
>>   * The PCI interface treats multi-function devices as independent
>>   * devices.  The slot/function address of each device is encoded
>> -- 
>> 1.7.9.5
>> 

-- 
Richard Yang
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