On 01/26/2015 11:36 AM, James Hogan wrote: > >> + raw_current_cpu_data.htw_seq++; \ > > not "if (!raw_current_cpu_data.htw_seq++)) {"? Why? on _stop() calls you just increment it. The _start() will do the right thing then. I think what you suggest it to move the if() condition from the _start() to _stop(). > >> write_c0_pwctl(read_c0_pwctl() & \ >> ~(1 << MIPS_PWCTL_PWEN_SHIFT)); \ >> back_to_back_c0_hazard(); \ >> + local_irq_restore(flags); \ >> } \ >> } while(0) >> >> #define htw_start() \ >> do { \ >> + unsigned long flags; \ >> + \ >> if (cpu_has_htw) { \ >> - write_c0_pwctl(read_c0_pwctl() | \ >> - (1 << MIPS_PWCTL_PWEN_SHIFT)); \ >> - back_to_back_c0_hazard(); \ >> + local_irq_save(flags); \ >> + if (!--raw_current_cpu_data.htw_seq) { \ >> + write_c0_pwctl(read_c0_pwctl() | \ >> + (1 << MIPS_PWCTL_PWEN_SHIFT)); \ >> + back_to_back_c0_hazard(); \ >> + } \ >> + local_irq_restore(flags); \ >> } \ >> } while(0) >> >> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c >> index dc49cf30c2db..5d6e59f20750 100644 >> --- a/arch/mips/kernel/cpu-probe.c >> +++ b/arch/mips/kernel/cpu-probe.c >> @@ -367,8 +367,10 @@ static inline unsigned int decode_config3(struct cpuinfo_mips *c) >> if (config3 & MIPS_CONF3_MSA) >> c->ases |= MIPS_ASE_MSA; >> /* Only tested on 32-bit cores */ >> - if ((config3 & MIPS_CONF3_PW) && config_enabled(CONFIG_32BIT)) >> + if ((config3 & MIPS_CONF3_PW) && config_enabled(CONFIG_32BIT)) { >> + c->htw_seq = 0; > > is that necessary, since cpu_data[] is global? I checked and it is not placed in the .data instead of .bss section so i was not sure if it is initialized properly. -- markos