On Mon, Dec 11, 2006 at 02:55:39PM +1100, Benjamin Herrenschmidt wrote: > On Fri, 2006-12-08 at 10:22 -0800, Stephen Hemminger wrote: > > plain text document attachment (mthca-rbc.patch) > > Use new pci interfaces to set read request tuning values > > Untested because of lack of hardware.
Sorry...I missed that. I have mthca HW on publicly available IA64 machines. I'll contact Steve off list to check if he is interested/time. > I'm worried by this... At no point do you check the host bridge > capabilities, and thus will happily set the max read req size to some > value larger than the max the host bridge can cope... > > I've been having exactly that problem on a number of setups, for > example, the sky2 cards tend to start with a value of 512 while the G5's > host bridge can't cope with more than 256 (iirc). The firmware fixes > that up properly on the G5 at least (but not on all machines), but if > you allow drivers to go tweak the value without a way to go check what > are the host bridge capabilities, you are toast. > > Of course, on PCI-X, this is moot, there is no clear definition on how > to get to a host bridge config space (if any) ... > So for PCI-X, if we want tat, we need a pcibios hook for the platform > to validate the size requested. Yes, agreed. grant - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/