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 Thu, Nov 06, 2014 at 11:12:02AM +0800, Wei Yang wrote:
>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).
>
>Hi, Yinghai,
>
>Do you have some historical story on the definition?
>

Hi,

I am not sure if I missed some mail. This is the last mail I sent, but no
reply I got yet. Is is ok to send an updated version?

>>
>>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.
>>
>>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
>Help you, Help me

-- 
Richard Yang
Help you, Help me