From 18d8d4d2287b790360ee58d2ace4896e2e10cbb6 Mon Sep 17 00:00:00 2001 From: Sean Paul Date: Tue, 16 Aug 2016 16:11:28 -0700 Subject: [PATCH] drm/rockchip: Convert psr_list_mutex to spinlock and use it This patch converts the psr_list_mutex to a spinlock and locks all access to psr_list to avoid races (however unlikely they were). Reviewed-by: Yakir Yang Signed-off-by: Sean Paul --- drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 2 +- drivers/gpu/drm/rockchip/rockchip_drm_drv.h | 2 +- drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 25 +++++++++++++++------ 3 files changed, 20 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c index b43fe5d93828..76eaf1de52e4 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c @@ -157,7 +157,7 @@ static int rockchip_drm_bind(struct device *dev) drm_dev->dev_private = private; INIT_LIST_HEAD(&private->psr_list); - mutex_init(&private->psr_list_mutex); + spin_lock_init(&private->psr_list_lock); drm_mode_config_init(drm_dev); diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h index 9c34c9e181d0..5c698456aa1c 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h +++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h @@ -63,7 +63,7 @@ struct rockchip_drm_private { struct drm_atomic_state *state; struct list_head psr_list; - struct mutex psr_list_mutex; + spinlock_t psr_list_lock; }; int rockchip_register_crtc_funcs(struct drm_crtc *crtc, diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c index a6d3bd25b905..bd25273a89bb 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c @@ -45,12 +45,18 @@ static struct psr_drv *find_psr_by_crtc(struct drm_crtc *crtc) { struct rockchip_drm_private *drm_drv = crtc->dev->dev_private; struct psr_drv *psr; + unsigned long flags; - list_for_each_entry(psr, &drm_drv->psr_list, list) + spin_lock_irqsave(&drm_drv->psr_list_lock, flags); + list_for_each_entry(psr, &drm_drv->psr_list, list) { if (psr->encoder->crtc == crtc) - return psr; + goto out; + } + psr = ERR_PTR(-ENODEV); - return ERR_PTR(-ENODEV); +out: + spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags); + return psr; } static void psr_state_work(struct work_struct *work) @@ -173,7 +179,9 @@ void rockchip_drm_psr_flush(struct drm_device *dev) { struct rockchip_drm_private *drm_drv = dev->dev_private; struct psr_drv *psr; + unsigned long flags; + spin_lock_irqsave(&drm_drv->psr_list_lock, flags); list_for_each_entry(psr, &drm_drv->psr_list, list) { if (psr->request_state == PSR_DISABLE) continue; @@ -183,6 +191,7 @@ void rockchip_drm_psr_flush(struct drm_device *dev) psr_set_state(psr, PSR_FLUSH); } + spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags); } EXPORT_SYMBOL(rockchip_drm_psr_flush); @@ -199,6 +208,7 @@ int rockchip_drm_psr_register(struct drm_encoder *encoder, { struct rockchip_drm_private *drm_drv = encoder->dev->dev_private; struct psr_drv *psr; + unsigned long flags; if (!encoder || !psr_set) return -EINVAL; @@ -215,9 +225,9 @@ int rockchip_drm_psr_register(struct drm_encoder *encoder, psr->encoder = encoder; psr->set = psr_set; - mutex_lock(&drm_drv->psr_list_mutex); + spin_lock_irqsave(&drm_drv->psr_list_lock, flags); list_add_tail(&psr->list, &drm_drv->psr_list); - mutex_unlock(&drm_drv->psr_list_mutex); + spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags); return 0; } @@ -235,8 +245,9 @@ void rockchip_drm_psr_unregister(struct drm_encoder *encoder) { struct rockchip_drm_private *drm_drv = encoder->dev->dev_private; struct psr_drv *psr, *n; + unsigned long flags; - mutex_lock(&drm_drv->psr_list_mutex); + spin_lock_irqsave(&drm_drv->psr_list_lock, flags); list_for_each_entry_safe(psr, n, &drm_drv->psr_list, list) { if (psr->encoder == encoder) { del_timer(&psr->flush_timer); @@ -244,6 +255,6 @@ void rockchip_drm_psr_unregister(struct drm_encoder *encoder) kfree(psr); } } - mutex_unlock(&drm_drv->psr_list_mutex); + spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags); } EXPORT_SYMBOL(rockchip_drm_psr_unregister); -- 2.20.1