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-rw-r--r--drivers/cpufreq/speedstep-lib.c3
-rw-r--r--drivers/cpufreq/speedstep-smi.c12
2 files changed, 15 insertions, 0 deletions
diff --git a/drivers/cpufreq/speedstep-lib.c b/drivers/cpufreq/speedstep-lib.c
index 7047821a7f8a..4ab7a2156672 100644
--- a/drivers/cpufreq/speedstep-lib.c
+++ b/drivers/cpufreq/speedstep-lib.c
@@ -400,6 +400,7 @@ unsigned int speedstep_get_freqs(enum speedstep_processor processor,
pr_debug("previous speed is %u\n", prev_speed);
+ preempt_disable();
local_irq_save(flags);
/* switch to low state */
@@ -464,6 +465,8 @@ unsigned int speedstep_get_freqs(enum speedstep_processor processor,
out:
local_irq_restore(flags);
+ preempt_enable();
+
return ret;
}
EXPORT_SYMBOL_GPL(speedstep_get_freqs);
diff --git a/drivers/cpufreq/speedstep-smi.c b/drivers/cpufreq/speedstep-smi.c
index 5fc96d5d656b..819229e824fb 100644
--- a/drivers/cpufreq/speedstep-smi.c
+++ b/drivers/cpufreq/speedstep-smi.c
@@ -156,6 +156,7 @@ static void speedstep_set_state(unsigned int state)
return;
/* Disable IRQs */
+ preempt_disable();
local_irq_save(flags);
command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
@@ -166,9 +167,19 @@ static void speedstep_set_state(unsigned int state)
do {
if (retry) {
+ /*
+ * We need to enable interrupts, otherwise the blockage
+ * won't resolve.
+ *
+ * We disable preemption so that other processes don't
+ * run. If other processes were running, they could
+ * submit more DMA requests, making the blockage worse.
+ */
pr_debug("retry %u, previous result %u, waiting...\n",
retry, result);
+ local_irq_enable();
mdelay(retry * 50);
+ local_irq_disable();
}
retry++;
__asm__ __volatile__(
@@ -185,6 +196,7 @@ static void speedstep_set_state(unsigned int state)
/* enable IRQs */
local_irq_restore(flags);
+ preempt_enable();
if (new_state == state)
pr_debug("change to %u MHz succeeded after %u tries "