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| author | Rob Herring <rob.herring@calxeda.com> | 2013-02-08 16:14:59 -0600 |
|---|---|---|
| committer | Rob Herring <rob.herring@calxeda.com> | 2013-04-10 18:27:11 -0500 |
| commit | c115739da801ea1ea20c48e2991ce6761496bef1 (patch) | |
| tree | 8d7632d56301903a8ab88a9121f2c1c1715958d8 | |
| parent | 3d5a96582303e28c48699f3faaf920ef7d43e6f2 (diff) | |
| download | linux-stable-c115739da801ea1ea20c48e2991ce6761496bef1.tar.gz linux-stable-c115739da801ea1ea20c48e2991ce6761496bef1.tar.bz2 linux-stable-c115739da801ea1ea20c48e2991ce6761496bef1.zip | |
ARM: sched_clock: allow changing to higher frequency counter
Allow multiple calls to setup_sched_clock and switch to the new counter
if it is higher frequency.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
| -rw-r--r-- | arch/arm/kernel/sched_clock.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index bd6f56b9ec21..040168e8a60d 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -20,6 +20,7 @@ struct clock_data { u64 epoch_ns; u32 epoch_cyc; u32 epoch_cyc_copy; + unsigned long rate; u32 mult; u32 shift; bool suspended; @@ -113,11 +114,14 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) u64 res, wrap; char r_unit; + if (cd.rate > rate) + return; + BUG_ON(bits > 32); WARN_ON(!irqs_disabled()); - WARN_ON(read_sched_clock != jiffy_sched_clock_read); read_sched_clock = read; sched_clock_mask = (1 << bits) - 1; + cd.rate = rate; /* calculate the mult/shift to convert counter ticks to ns. */ clocks_calc_mult_shift(&cd.mult, &cd.shift, rate, NSEC_PER_SEC, 0); |