On 08/17/2016 09:11 AM, Sean Paul wrote: > This patch converts the psr_list_mutex to a spinlock and locks > all access to psr_list to avoid races (however unlikely they > were). > > Signed-off-by: Sean Paul <seanpaul at chromium.org> Reviewed-by: Yakir Yang <ykk at rock-chips.com> > --- > > Changes in v2: > - Rebased on https://cgit.freedesktop.org/~seanpaul/dogwood/log/?h=for-next > > 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 b43fe5d9..76eaf1d 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 9c34c9e..5c69845 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 a6d3bd25..bd25273 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);
