Re: Q: PCI-X @ 266MHz on HP rx6600 (Qlogic 4Gb FC HBA)

[Andrew Patterson <andrew.patterson@hp.com>]

On Thu, 2007-07-26 at 23:23 -0700, Andrew Vasquez wrote:
> On Thu, 26 Jul 2007, Andrew Patterson wrote:
> 
> > On Thu, 2007-07-26 at 15:36 +0200, Ulrich Windl wrote:
> > > Hi,
> > > 
> > > I have a question: The Qlogic ISP2422 chip is said to handle PCI-X 266MHz. So does 
> > > the HP Itanium2 server rx6600. Basically that was the reason to select that 
> > > server. The FC-HBA is in a 266 MHz capable slot. However when booting SLES10 SP1 
> > > for IA64, the logs say:
> 
> There's a mixup here in terminology...  The QLA2460 card which you
> have does in fact support 'PCI-X 266'...
> 
> > > <6>QLogic Fibre Channel HBA Driver
> > > <6>GSI 49 (level, low) -> CPU 3 (0x0300) vector 51
> > > <6>ACPI: PCI Interrupt 0000:0f:01.0[A] -> GSI 49 (level, low) -> IRQ 51
> > > <6>qla2xxx 0000:0f:01.0: Found an ISP2422, irq 51, iobase 0xc0000000b0040000
> > > [...]
> > > <6>qla2xxx 0000:0f:01.0: LOOP UP detected (4 Gbps).
> > > <6>qla2xxx 0000:0f:01.0: Topology - (F_Port), Host Loop address 0x0
> > > <6>scsi0 : qla2xxx
> > > <6>qla2xxx 0000:0f:01.0:
> > > <4> QLogic Fibre Channel HBA Driver: 8.01.07-k3
> > > <4>  QLogic HP AB378-60001 -
> > > <4>  ISP2422: PCI-X Mode 2 (133 MH4.00.26 [IP]  @ 0000:0f:01.0 hdma+, host#=0, 
> > > fw=4.00.26 [IP]
> 
> The 33/66/100/133 values refer to the bus-clock speed at which the
> card is operating.  As is seen here (although a bit truncated --
> separate issue, I'll try to see if I can reproduce this on one of my
> HPQ rigs), the card is inserted into a PCI-X Mode-2 capable 133MHz
> (bus clock) slot.  When operating under this mode, each data-phase
> between two devices is divided into 2 sub-phases, effectively doubling
> the transfer-data-rate to 266Mhz.

I guess the proper terminology would be 266 MT/s (Mega
Transfers/second). Looking through the PSI_SIG PCI-X 2.0 marketing
blurbs, they use MHz a lot when referring to MT/S. So I would still
consider this to be a minor bug.  The user wants to know the transfer
rate, not the actual frequency of the bus.  Maybe just print out the
mode used instead, e.g., "PCI-X 266"?

> 
> > > <5>  Vendor: HP        Model: HSV200            Rev: 6100
> > > <5>  Type:   RAID                               ANSI SCSI revision: 02
> > > <5> 0:0:0:0: Attached scsi generic sg0 type 12
> > > 
> > > Now does Linux support the speed of 266 MHz, and is it just displayed incorrectly, 
> > > or doesn't Linux support the speed of 266MHz yet?
> > 
> > This is a bug in the driver.  The lookup table only goes to 133 MHz.
> > 
> > static char *pci_bus_modes[] = {
> >                 "33", "66", "100", "133",
> > 
> > The same problem exists in the scsi_misc tree.
> 
> Regards,
> Andrew Vasquez

-- 
Andrew Patterson
Hewlett-Packard Company