On Fri, Nov 06, 2020 at 01:52:01PM +1100, Finn Thain wrote:
On Fri, 23 Oct 2020, Geert Uytterhoeven wrote:
The arm/rpc timer seems to be roughly in the same category as most
of the m68k ones or the i8253 counter on a PC. It's possible that
some of them could use the same logic as
drivers/clocksource/i8253.o as long as there is any hardware
oneshot mode.
There appear to be 15 platforms in that category. 4 have no
clocksource besides the jiffies clocksource, meaning there's no
practical alternative to using a periodic tick, like you did in your
RFC patch:
arch/m68k/apollo/config.c
arch/m68k/q40/q40ints.c
arch/m68k/sun3/sun3ints.c
arch/m68k/sun3x/time.c
Do any of these have users? I'm fairly sure sun3x has never worked in
mainline, sun3 seems to still need the same few patches it did 20
years ago. I couldn't find much about Linux on Apollo or q40, the
information on the web for either of them seems to all be for
linux-2.4 kernels.
They probably don't have any users.
I have access to several Sun 3 machines but no time to work on that port,
unfortunately.
Are these 4 platforms (those with no clocksource besides the "jiffies"
clocksource) the only reason for CONFIG_TIME_LOW_RES on m68k?
Sun3x was probably at least as close (if not closer) than Sun3 to
working in mainline back in the day, but unfortunately I'm in the same
place as Finn... I've got the hardware, but time is harder to come
by.
-- Sam
