diff options
| author | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 13:56:16 +0200 |
|---|---|---|
| committer | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 13:56:16 +0200 |
| commit | ff67a6b9aaddb2dea6ed4a3f7df8a0c6acf131c2 (patch) | |
| tree | 34d81901340c14191fab6e0c5a424f45385ae2aa /drivers/cpufreq/speedstep-smi.c | |
| parent | e7549b926dd3ceec048f5689df90d4ec970c9419 (diff) | |
| download | kernel_samsung_smdk4412-ff67a6b9aaddb2dea6ed4a3f7df8a0c6acf131c2.zip kernel_samsung_smdk4412-ff67a6b9aaddb2dea6ed4a3f7df8a0c6acf131c2.tar.gz kernel_samsung_smdk4412-ff67a6b9aaddb2dea6ed4a3f7df8a0c6acf131c2.tar.bz2 | |
last driver import from 3.2.72 for now
Diffstat (limited to 'drivers/cpufreq/speedstep-smi.c')
| -rw-r--r-- | drivers/cpufreq/speedstep-smi.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/cpufreq/speedstep-smi.c b/drivers/cpufreq/speedstep-smi.c index c76ead3..8a97f94 100644 --- a/drivers/cpufreq/speedstep-smi.c +++ b/drivers/cpufreq/speedstep-smi.c @@ -187,6 +187,7 @@ static void speedstep_set_state(unsigned int state) return; /* Disable IRQs */ + preempt_disable(); local_irq_save(flags); command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff); @@ -197,9 +198,19 @@ 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__( @@ -216,6 +227,7 @@ 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 " |