>>>>> "Paul" == Paul Mackerras <[EMAIL PROTECTED]> writes:
Paul> Jesse Barnes writes: >> So ultimately mmiowb() is the only thing drivers really have to >> care about on Altix (assuming they do DMA mapping correctly), and >> the rules for that are fairly simple. Then they can additionally >> use read_relaxed() to optimize performance a bit (quite a bit on >> big systems). Paul> If I can be sure that all the drivers we care about on PPC use Paul> mmiowb correctly, I can reduce or eliminate the barrier in Paul> write*, which would be nice. Paul> Which drivers have been audited to make sure they use mmiowb Paul> correctly? In particular, has the USB driver been audited? I think the primary drivers we've looked at are drivers/net/tg3.c, drivers/net/s2io.c, drivers/scsi/qla1280.c, and possibly the qla[234]xxx series - thats probably it! While we have USB on the systems, I don't think anyone has spend a lot of time verifying it in this context. At least the keyboard and mouse I have on this box seems to behave. Cheers, Jes - To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
