Re: SCSI QLA not working on latest *-mm SN2

Grant Grundler
2004-09-22T01:44:30Z

On Tue, Sep 21, 2004 at 06:16:52PM -0700, Jeremy Higdon wrote:
> First let's make sure that we like it best.
>
> The other alternative is an explicit I/O barrier.
>
> writel(high-water, request-in)
> mmiob() /* memory-mapped I/O barrier */
> spin_unlock(hostlock)

I strongly prefer a seperate function call.

I'm wondering if one for write posting and a different for write ordering
would be called for. These are really distinct uses but I'm not sure
it's a distinction that's clear to most folks and they will get misused.
If not, then io_mwb() would be my preference.

> versus
>
> writel(high-water, request-in)
> spin_unlock_iob(hostlock)

More variants of spinlocks?
When to use and how to implement it become even less clear.

thanks,
grant