On Thu, Jun 19, 2014 at 05:40:49PM +0100, Tomasz Figa wrote: > On 19.06.2014 18:31, Doug Anderson wrote: > >>> My personal vote would be to submit a patch to change "cycles_t" to > >>> always be 32-bits. Given that 32-bits was fine for udelay() for ARM > >>> that seems sane and simple. If someone later comes up with a super > >>> compelling reason why we need 64-bit timers for udelay (really??) then > >>> they can later add all the complexity needed. > >> > >> Yes, this could work. I'm not sure what else cycles_t is used for, though. > > > > True, it is a bit questionable to change this since it's a type that's > > not obviously just for udelay(). Perhaps a better option would be to > > make a new typedef for the result of read_current_timer(). ...or just > > change it to return a u32? > > > > Sounds good to me, but let's hear other opinions. I'm adding Will and > Jonathan as they wrote the ARM delay timer code. I think cycles_t is only used for small interval calculations at the moment, but I remember Ted mentioning something about using it (or something similar) as a source of early entropy, in which case the more bits the better. That said, I can't find any code in the tree to that effect. Will -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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