This patch cleans up interrupt disabling in speedstep-smi and speedstep-lib. It doesn't fix any bug.
speedstep_get_freqs in speedstep-lib may be called from speedstep-smi or speedstep-ich. When it is called from speedstep-ich, it needs to calculate transition latency. When it is called from speedstep-smi, transition latency doesn't have to be calculated. The function speedstep_set_state in speedstep-smi needs to enable interrupts. Previously it enabled interrupts even if it was called with disabled interrupts, but it is dirty. This patch changes speedstep_get_freqs so that it disables interrupts only when it is called from speedstep-ich and when it is measuring the transition latency. This avoids much of the code dirtiness. Signed-off-by: Mikulas Patocka <[email protected]> --- drivers/cpufreq/speedstep-lib.c | 13 ++++++------- drivers/cpufreq/speedstep-smi.c | 11 ++++------- 2 files changed, 10 insertions(+), 14 deletions(-) Index: linux-3.14-rc1/drivers/cpufreq/speedstep-lib.c =================================================================== --- linux-3.14-rc1.orig/drivers/cpufreq/speedstep-lib.c 2014-02-03 19:06:21.000000000 +0100 +++ linux-3.14-rc1/drivers/cpufreq/speedstep-lib.c 2014-02-03 19:06:26.000000000 +0100 @@ -400,9 +400,6 @@ unsigned int speedstep_get_freqs(enum sp pr_debug("previous speed is %u\n", prev_speed); - preempt_disable(); - local_irq_save(flags); - /* switch to low state */ set_state(SPEEDSTEP_LOW); *low_speed = speedstep_get_frequency(processor); @@ -414,15 +411,19 @@ unsigned int speedstep_get_freqs(enum sp pr_debug("low speed is %u\n", *low_speed); /* start latency measurement */ - if (transition_latency) + if (transition_latency) { + local_irq_save(flags); do_gettimeofday(&tv1); + } /* switch to high state */ set_state(SPEEDSTEP_HIGH); /* end latency measurement */ - if (transition_latency) + if (transition_latency) { do_gettimeofday(&tv2); + local_irq_restore(flags); + } *high_speed = speedstep_get_frequency(processor); if (!*high_speed) { @@ -464,8 +465,6 @@ unsigned int speedstep_get_freqs(enum sp } out: - local_irq_restore(flags); - preempt_enable(); return ret; } Index: linux-3.14-rc1/drivers/cpufreq/speedstep-smi.c =================================================================== --- linux-3.14-rc1.orig/drivers/cpufreq/speedstep-smi.c 2014-02-03 19:06:21.000000000 +0100 +++ linux-3.14-rc1/drivers/cpufreq/speedstep-smi.c 2014-02-03 19:06:26.000000000 +0100 @@ -148,16 +148,16 @@ static int speedstep_smi_get_freqs(unsig static void speedstep_set_state(unsigned int state) { unsigned int result = 0, command, new_state, dummy; - unsigned long flags; unsigned int function = SET_SPEEDSTEP_STATE; unsigned int retry = 0; if (state > 0x1) return; - /* Disable IRQs */ + WARN_ON_ONCE(irqs_disabled()); + + /* Disable preemption so that other processes don't run */ preempt_disable(); - local_irq_save(flags); command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); @@ -177,9 +177,7 @@ static void speedstep_set_state(unsigned */ pr_debug("retry %u, previous result %u, waiting...\n", retry, result); - local_irq_enable(); mdelay(retry * 50); - local_irq_disable(); } retry++; __asm__ __volatile__( @@ -194,8 +192,7 @@ static void speedstep_set_state(unsigned ); } while ((new_state != state) && (retry <= SMI_TRIES)); - /* enable IRQs */ - local_irq_restore(flags); + /* enable preemption */ preempt_enable(); if (new_state == state) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
