On Tue, 13 Nov 2018, Russell King - ARM Linux wrote: > On Tue, Nov 13, 2018 at 02:39:00PM +1100, Finn Thain wrote: > > > > You could remove the old arch_gettimeoffset API without dropping any > > platforms. > > > > If no-one converts a given platform to the clocksource API it would mean > > that the default 'jiffies' clocksource will get used on that platform. > > > > Clock resolution and timer precision would be degraded, but that might not > > matter. > > > > Anyway, if someone who has this hardware is willing to test a clocksource > > API conversion, they can let me know and I'll attempt that patch. > > There's reasons why that's not appropriate - such as not having two > separate timers in order to supply a clocksource and separate clock > event. > > Not all hardware is suited to the clocksource + clockevent idea. >
Sorry, I don't follow. AFAIK, clocksources and clock event devices are orthogonal concepts. There are platforms with !ARCH_USES_GETTIMEOFFSET && !GENERIC_CLOCKEVENTS (and every other combination). A clocksource read method just provides a cycle count, and in this sense arch_gettimeoffset() is equivalent to a clocksource. If these two arm platforms have an existing clock event device which somehow precludes any new clocksources, why doesn't that also render arch_gettimeoffset() impossible? --
