Re: [PATCH v4 2/4] drm/rockchip: add an common abstracted PSR driver

Yakir,

On Wed, Jul 13, 2016 at 9:15 PM, Yakir Yang ykk@rock-chips.com wrote:

+static void psr_set_state(struct psr_drv *psr, enum psr_state state) +{

•   mutex_lock(&psr->state_mutex);
  

•   if (psr->state == state) {
  

•           mutex_unlock(&psr->state_mutex);
  

•           return;
  

•   }
  

•   psr->state = state;
  

•   switch (state) {
  

•   case PSR_ENABLE:
  

•           psr->set(psr->encoder, true);
  

•           break;
  

•   case PSR_DISABLE:
  

•   case PSR_FLUSH:
  

•           psr->set(psr->encoder, false);
  

•           break;
  

•   };
  

•   mutex_unlock(&psr->state_mutex);
  

+}

+static void psr_flush_handler(unsigned long data) +{

•   struct psr_drv *psr = (struct psr_drv *)data;
  

•   if (!psr || psr->state != PSR_FLUSH)
  

•           return;
  

•   psr_set_state(psr, PSR_ENABLE);
  

As mentioned in a separate thread, this is probably not OK. psr_set_state() grabs a mutex and that might sleep. ...but psr_flush_handler() is a timer. I'm nearly certain that timers can't sleep.

I believe this is the source of "sleeping function called from invalid context" that I've seen at times.

-Doug