From eec85347c7efa72fd45d3f428bab5d6c108db1f2 Mon Sep 17 00:00:00 2001 From: Sean Paul Date: Tue, 16 Aug 2016 16:28:31 -0700 Subject: [PATCH] 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 Signed-off-by: Sean Paul --- drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 26 ++++++++++++++------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c index 4c645d757da5..5bd54f2c6ce1 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c @@ -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; -- 2.39.5