Re: [PATCH] pci: change msi-x vector to 32bit

[ebiederm@xmission.com (Eric W. Biederman)]

Jesse Barnes <jbarnes@virtuousgeek.org> writes:

> On Friday, August 15, 2008 7:36 pm Yinghai Lu wrote:
>> we are using 28bit pci (bus/dev/fn + 12 bits) as irq number, so the
>> cache for irq number should be 32 bit too.
>>
>> Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
>> Cc: Andrew Vasquez <andrew.vasquez@qlogic.com>
>>
>> ---
>>  drivers/scsi/qla2xxx/qla_def.h |    2 +-
>>  include/linux/pci.h            |    2 +-
>>  2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> Index: linux-2.6/drivers/scsi/qla2xxx/qla_def.h
>> ===================================================================
>> --- linux-2.6.orig/drivers/scsi/qla2xxx/qla_def.h
>> +++ linux-2.6/drivers/scsi/qla2xxx/qla_def.h
>> @@ -2109,7 +2109,7 @@ struct scsi_qla_host;
>>
>>  struct qla_msix_entry {
>>  	int have_irq;
>> -	uint16_t msix_vector;
>> +	uint32_t msix_vector;
>>  	uint16_t msix_entry;
>>  };
>>
>> Index: linux-2.6/include/linux/pci.h
>> ===================================================================
>> --- linux-2.6.orig/include/linux/pci.h
>> +++ linux-2.6/include/linux/pci.h
>> @@ -730,7 +730,7 @@ enum pci_dma_burst_strategy {
>>  };
>>
>>  struct msix_entry {
>> -	u16 	vector;	/* kernel uses to write allocated vector */
>> +	u32	vector;	/* kernel uses to write allocated vector */
>>  	u16	entry;	/* driver uses to specify entry, OS writes */
>>  };
>
> I see a lot of smoke about this, but not a clear consensus.  It sounds like no 
> one objects to making the MSI vector field 32 bits, but there were a lot of 
> concerns about IRQ vector naming/numbering in general?  And I assume this 
> particular patch isn't 2.6.27 material...

There is no need for this particular patch in 2.6.27.
It is a trivial bug fix so it can go in whenever.

Mostly this is a discussion about code that should land in the 2.6.28
timeframe assuming all is well.

Eric