diff options
| author |   Atsushi Nemoto <anemo@mba.ocn.ne.jp> | 2007-10-23 21:55:42 +0900 |
|---|---|---|
| committer |   Ralf Baechle <ralf@linux-mips.org> | 2007-10-29 19:35:35 +0000 |
| commit | 3a6c43a78763da67d4049745ce35122734e89fbc (patch) | |
| tree | 4889b4534b28629010d7a5e191edd43601b0cfe1 /arch | |
| parent | [MIPS] time: Fix cevt-r4k.c for 64-bit kernel (diff) | |
| download | linux-dev-3a6c43a78763da67d4049745ce35122734e89fbc.tar.xz linux-dev-3a6c43a78763da67d4049745ce35122734e89fbc.zip | |
[MIPS] time: Make c0_compare_int_usable faster
Try increasingly longer time periods starting of at 0x10 cycles. This
should be fast on hardware and work nicely with emulators.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/kernel/cevt-r4k.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c index 7274fd2513f9..a59f67ff301e 100644 --- a/arch/mips/kernel/cevt-r4k.c +++ b/arch/mips/kernel/cevt-r4k.c @@ -179,7 +179,7 @@ static int c0_compare_int_pending(void) static int c0_compare_int_usable(void) { - const unsigned int delta = 0x300000; + unsigned int delta; unsigned int cnt; /* @@ -192,9 +192,15 @@ static int c0_compare_int_usable(void) return 0; } - cnt = read_c0_count(); - cnt += delta; - write_c0_compare(cnt); + for (delta = 0x10; delta <= 0x400000; delta <<= 1) { + cnt = read_c0_count(); + cnt += delta; + write_c0_compare(cnt); + irq_disable_hazard(); + if ((int)(read_c0_count() - cnt) < 0) + break; + /* increase delta if the timer was already expired */ + } while ((int)(read_c0_count() - cnt) <= 0) ; /* Wait for expiry */ |