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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-09-23 13:24:10 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-09-23 13:24:10 -0700 |
| commit | dc4fea795bf7e3f80dbfa3a40b8ab89427e9aed5 (patch) | |
| tree | 1926c96f145965c393a2c8ab523c327dd1a241cf /arch/mips/include/asm/timex.h | |
| parent | c8f2efc8f636506e0f0c2ba4035382076875f0c1 (diff) | |
| parent | 9d23108df359e572a0dca0b631bfee9f5e0fa9ea (diff) | |
| download | linux-dc4fea795bf7e3f80dbfa3a40b8ab89427e9aed5.tar.bz2 | |
Merge branch 'master' into usb-next
We have USB fixes now in Linus's tree that we need to properly sort out
with reverts and the like in the usb-next branch, so merge them together
and do it by hand.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/mips/include/asm/timex.h')
| -rw-r--r-- | arch/mips/include/asm/timex.h | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/arch/mips/include/asm/timex.h b/arch/mips/include/asm/timex.h index 6529704aa73a..c5424757da65 100644 --- a/arch/mips/include/asm/timex.h +++ b/arch/mips/include/asm/timex.h @@ -10,7 +10,9 @@ #ifdef __KERNEL__ +#include <asm/cpu-features.h> #include <asm/mipsregs.h> +#include <asm/cpu-type.h> /* * This is the clock rate of the i8253 PIT. A MIPS system may not have @@ -33,9 +35,38 @@ typedef unsigned int cycles_t; +/* + * On R4000/R4400 before version 5.0 an erratum exists such that if the + * cycle counter is read in the exact moment that it is matching the + * compare register, no interrupt will be generated. + * + * There is a suggested workaround and also the erratum can't strike if + * the compare interrupt isn't being used as the clock source device. + * However for now the implementaton of this function doesn't get these + * fine details right. + */ static inline cycles_t get_cycles(void) { - return 0; + switch (boot_cpu_type()) { + case CPU_R4400PC: + case CPU_R4400SC: + case CPU_R4400MC: + if ((read_c0_prid() & 0xff) >= 0x0050) + return read_c0_count(); + break; + + case CPU_R4000PC: + case CPU_R4000SC: + case CPU_R4000MC: + break; + + default: + if (cpu_has_counter) + return read_c0_count(); + break; + } + + return 0; /* no usable counter */ } #endif /* __KERNEL__ */ |