On Thu, Aug 01, 2013 at 08:15:50AM +0200, John Crispin wrote: > >Whatever works for you. I still would like to understand why plat_time_init() > >is not suitable for John's specific use case. > > Hi Florian, > > the reason is that fixing it in plat_time_init() works around the > real problem. the double request of the irq is a symptom of the > actual problem, which is, that the cevt-r4k sets up the timer during > init and not during setup. additionally, plat_time_init is used to > probe the cevt drivers from OF already. currently the mips code just > assumes that on a r4k we always have and want to run the cevt-r4k. > this assumption is wrong and can quickly be fixed by making the > cevt-r4k use the correct api. > > also fixing it this way allows the user to control the clocksource > and change it at runtime via sysfs, a feature als not working > currently on r4k as the cevt driver did not implement the set_mode() > handler correctly. to be quite honest, i cannot think of a single > way in which this can be fixed cleanly in the ralink > plat_time_init() without using some weird heuristic. also if i fix > this inside ralink plat_time_init() it is fixed only on ralink SoC > and not on any other platform. setup_irq() may fail but set_mode doesn't have a way to communicate an error - other than leaving back a half-wrecked system so set_mode is not a good place to do that kind of job. How about using get_c0_compare_int() for a solution? Currently get_c0_compare_int() can not return an error. If it could return a negative value to indicate the unavailability of an interrupt for cevt-r4k's use, that interrupt would be available for alternative use. Ralf
