mirror of https://gitee.com/openkylin/linux.git
a904f74785
From Dave Johnson <djohnson+linuxmips@sw.starentnetworks.com>:
sb1250_gettimeoffset() simply reads the current cpu 0 timer remaining
value, however once this counter reaches 0 and the interrupt is raised,
it immediately resets and begins to count down again.
If sb1250_gettimeoffset() is called on cpu 1 via do_gettimeofday() after
the timer has reset but prior to cpu 0 processing the interrupt and
taking write_seqlock() in timer_interrupt() it will return a full value
(or close to it) causing time to jump backwards 1ms. Once cpu 0 handles
the interrupt and timer_interrupt() gets far enough along it will jump
forward 1ms.
Fix this problem by implementing mips_hpt_*() on sb1250 using a spare
timer unrelated to the existing periodic interrupt timers. It runs at
1Mhz with a full 23bit counter. This eliminated the custom
do_gettimeoffset() for sb1250 and allowed use of the generic
fixed_rate_gettimeoffset() using mips_hpt_*() and timerhi/timerlo.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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| .. | ||
| bcm1480_int.h | ||
| bcm1480_l2c.h | ||
| bcm1480_mc.h | ||
| bcm1480_regs.h | ||
| bcm1480_scd.h | ||
| bigsur.h | ||
| board.h | ||
| carmel.h | ||
| sb1250.h | ||
| sb1250_defs.h | ||
| sb1250_dma.h | ||
| sb1250_genbus.h | ||
| sb1250_int.h | ||
| sb1250_l2c.h | ||
| sb1250_ldt.h | ||
| sb1250_mac.h | ||
| sb1250_mc.h | ||
| sb1250_regs.h | ||
| sb1250_scd.h | ||
| sb1250_smbus.h | ||
| sb1250_syncser.h | ||
| sb1250_uart.h | ||
| sentosa.h | ||
| swarm.h | ||
| trace_prof.h | ||