> On Fri, Nov 02, 2001 at 12:26:18PM -0800, Christine Ames wrote: > > > Greetings, > > > > I'm looking for a way to "busy wait" <= 400 nanoseconds. > > > > In _Linux_Device_Drivers_ I've found udelay(for micro > > seconds) and mdelay(for milli seconds), but they state (2nd > > edition, page 189) that "Currently, support for delays longer > > than a few microseconds and shorter than a timer tick is very > > inefficient." I found no further discussion. > > > > "Inefficient" or not, I need a cross-platform/cross-kernel > > way to stall <= 400ns while my hardware gets back to me. Am > > I stuck, or is there a way? > > There's no way currently to do that, the best you can do is udelay(1), which is > 1ns. Any more, and you'll need to write your own function, based on udelay, it's > not *that* difficult, divide the magic constant by 2 to get roughly 550ns, I'd > think... I thing you mean 1ms, not 1ns... or else it would just be udelay(400), wouldn't it? ;) Grs, Marc. - Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/
