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drm/rockchip: Use a spinlock to protect psr state 

The handling of psr state is racey, shore that up with
a per-psr driver lock.

Reviewed-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
This commit is contained in:
Sean Paul 2016-08-16 16:28:31 -07:00
parent 23c0f3dcc0
commit eec85347c7
1 changed files with 17 additions and 9 deletions
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26
drivers/gpu/drm/rockchip/rockchip_drm_psr.c
View File

@ -30,6 +30,7 @@ struct psr_drv {
struct list_head list;
struct drm_encoder *encoder;
spinlock_t lock;
enum psr_state state;
struct timer_list flush_timer;
@ -55,7 +56,7 @@ out:
return psr;
}
static void psr_set_state(struct psr_drv *psr, enum psr_state state)
static void psr_set_state_locked(struct psr_drv *psr, enum psr_state state)
{
/*
* Allowed finite state machine:
@ -75,7 +76,6 @@ static void psr_set_state(struct psr_drv *psr, enum psr_state state)
if (state == PSR_FLUSH && psr->state == PSR_DISABLE)
return;
/* Only wrote in this work, no need lock protection */
psr->state = state;
/* Allow but no need hardware change, just need assign the state */
@ -95,18 +95,28 @@ static void psr_set_state(struct psr_drv *psr, enum psr_state state)
}
}
static void psr_set_state(struct psr_drv *psr, enum psr_state state)
{
unsigned long flags;
spin_lock_irqsave(&psr->lock, flags);
psr_set_state_locked(psr, state);
spin_unlock_irqrestore(&psr->lock, flags);
}
static void psr_flush_handler(unsigned long data)
{
struct psr_drv *psr = (struct psr_drv *)data;
unsigned long flags;
if (!psr)
return;
/* State changed between flush time, then keep it */
if (psr->state != PSR_FLUSH)
return;
psr_set_state(psr, PSR_ENABLE);
spin_lock_irqsave(&psr->lock, flags);
if (psr->state == PSR_FLUSH)
psr_set_state_locked(psr, PSR_ENABLE);
spin_unlock_irqrestore(&psr->lock, flags);
}
/**
@ -167,9 +177,6 @@ void rockchip_drm_psr_flush(struct drm_device *dev)
spin_lock_irqsave(&drm_drv->psr_list_lock, flags);
list_for_each_entry(psr, &drm_drv->psr_list, list) {
if (psr->state == PSR_DISABLE)
continue;
mod_timer(&psr->flush_timer,
round_jiffies_up(jiffies + PSR_FLUSH_TIMEOUT));
@ -202,6 +209,7 @@ int rockchip_drm_psr_register(struct drm_encoder *encoder,
return -ENOMEM;
setup_timer(&psr->flush_timer, psr_flush_handler, (unsigned long)psr);
spin_lock_init(&psr->lock);
psr->state = PSR_DISABLE;
psr->encoder = encoder;