On Tue, 2009-03-10 at 19:22 -0500, Timur Tabi wrote: > > Alan did have one valid point though. Determining how long to loop > for is architecture-specific. Using jiffies is bad, because even one > jiffy is too long. Adding a udelay() inside the loop means that it > only checks he condition every microsecond. So the real solution is > to use keep looping until a certain amount of time has passed. This > means using an architecture-specific timebase register.
> Now we can create a generic version of the function that uses jiffies, > and then arch-specific versions where possible. But Alan still needs > to be convinced. I already posted a length rebuttal to his email, but > I haven't gotten a reply yet. > There are several aspects here: - The amount of time to wait should be specified by the caller since it's generally going to come from HW specs - The amount of time between the polls ... that could also be an argument to the macro, not sure there - The precision of the actual wait calls... I vote for microseconds for everything and udelay. The arch will do its best. Cheers, Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
