On Sat, 19 Jun 2004 17:22:44 -0400, Jeff Garzik wrote:
> Roger Luethi wrote:
> >+#define RHINE_WAIT_FOR(condition) do { \
> >+ int i=1024; \
> >+ while (!(condition) && --i) \
> >+ ; \
> >+ if (debug > 1 && i < 512) \
> >+ printk(KERN_INFO "%s: %4d cycles used @ %s:%d\n", \
> >+ DRV_NAME, 1024-i, __func__, __LINE__); \
> >+} while(0)
>
> empty loops need at least a cpu_relax(), if not a true delay to
> guarantee the timing you desire.
Sure, I can add a cpu_relax(). FWIW, though, this macro is only used
for one purpose: Waiting for registers to reach a certain value. IOW:
Every evaluation of "condition" causes an I/O operation (inb or readb).
> Also, it would be nice to change the name, since there isn't anything
> rhine-specific about this macro.
Hmm... It relies on DRV_NAME :-). It's trivial to write a more generic
version if there's interest. I'm just trying to keep the namespace
clean. ... I just checked: drivers/macintosh/via-cuda.c defines a macro
WAIT_FOR that does pretty much the same. Does that already make the
case for a generic function for everyone to use?
Roger
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