On Fri, Nov 02, 2018 at 04:38:48PM -0700, Jeykumar Sankaran wrote: > On 2018-11-01 12:18, Sean Paul wrote: > > On Wed, Oct 31, 2018 at 05:19:05PM -0700, Jeykumar Sankaran wrote: > > > msm maintains a separate structure to define vblank > > > work definitions and a list to track events submitted > > > to the display worker thread. We can avoid these > > > redundant list and its protection mechanism, if we > > > subclass the work object to encapsulate vblank > > > event parameters. > > > > > > Signed-off-by: Jeykumar Sankaran <jsanka@xxxxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/msm/msm_drv.c | 70 > > ++++++++++++------------------------------- > > > drivers/gpu/drm/msm/msm_drv.h | 7 ----- > > > 2 files changed, 19 insertions(+), 58 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/msm/msm_drv.c > > b/drivers/gpu/drm/msm/msm_drv.c > > > index 1f384b3..67a96ee 100644 > > > --- a/drivers/gpu/drm/msm/msm_drv.c > > > +++ b/drivers/gpu/drm/msm/msm_drv.c /snip > > > static int vblank_ctrl_queue_work(struct msm_drm_private *priv, > > > int crtc_id, bool enable) > > > { > > > - struct msm_vblank_ctrl *vbl_ctrl = &priv->vblank_ctrl; > > > - struct vblank_event *vbl_ev; > > > - unsigned long flags; > > > + struct msm_vblank_work *vbl_work; > > > > > > - vbl_ev = kzalloc(sizeof(*vbl_ev), GFP_ATOMIC); > > > - if (!vbl_ev) > > > + vbl_work = kzalloc(sizeof(*vbl_work), GFP_ATOMIC); > > > + if (!vbl_work) > > > return -ENOMEM; > > > > > > - vbl_ev->crtc_id = crtc_id; > > > - vbl_ev->enable = enable; > > > + kthread_init_work(&vbl_work->work, vblank_ctrl_worker); > > > > > > - spin_lock_irqsave(&vbl_ctrl->lock, flags); > > > - list_add_tail(&vbl_ev->node, &vbl_ctrl->event_list); > > > - spin_unlock_irqrestore(&vbl_ctrl->lock, flags); > > > + vbl_work->crtc_id = crtc_id; > > > + vbl_work->enable = enable; > > > + vbl_work->priv = priv; > > > > > > - kthread_queue_work(&priv->disp_thread.worker, &vbl_ctrl->work); > > > + kthread_queue_work(&priv->disp_thread.worker, &vbl_work->work); > > > > So I think this can get even more simplified. In the short term, you can > > just > > use the systemwq to do the enable and disable. > > you mean priv->wq? > I meant the system workqueue, we probably don't need our own for this. > > > > In the long term, the enable_vblank/disable_vblank functions should be > > optimized so they don't sleep. I took a quick look at them perhaps this > > is > > all because of the crtc_lock mutex? That lock seems a bit suspicious to > > me, > > especially being dropped around the pm_runtime calls in > > _dpu_crtc_vblank_enable_no_lock(). I think we could probably rely on the > > modeset > > locks for some of these functions, and perhaps convert it to a spinlock > > if > > we > > can't get rid of it entirely. > > crtc_lock has a history of usage in the downstream driver. It was introduced > to protect > vblank variables when vblank requests were handled in the user thread > (not the display thread). When event threads were introduced to receive > encoder events, the lock was further expanded to protect few more vars. It > was > also needed to synchronize CRTC accesses between debugfs dump calls > and display thread. The debugfs case can be solved pretty easily by using the modeset locks. I haven't looked closely at the event threads, could we convert crtc_lock to a spinlock and then make vblank enable/disable synchronous? Sean > > Would like to deal with this cleanup bit later once we lose these extra > threads. > > Thanks and Regards, > Jeykumar S. > > > > > Sean > > > > > > > > return 0; > > > } > > > @@ -269,20 +252,8 @@ static int msm_drm_uninit(struct device *dev) > > > struct msm_drm_private *priv = ddev->dev_private; > > > struct msm_kms *kms = priv->kms; > > > struct msm_mdss *mdss = priv->mdss; > > > - struct msm_vblank_ctrl *vbl_ctrl = &priv->vblank_ctrl; > > > - struct vblank_event *vbl_ev, *tmp; > > > int i; > > > > > > - /* We must cancel and cleanup any pending vblank enable/disable > > > - * work before drm_irq_uninstall() to avoid work re-enabling an > > > - * irq after uninstall has disabled it. > > > - */ > > > - kthread_flush_work(&vbl_ctrl->work); > > > - list_for_each_entry_safe(vbl_ev, tmp, &vbl_ctrl->event_list, node) > > { > > > - list_del(&vbl_ev->node); > > > - kfree(vbl_ev); > > > - } > > > - > > > kthread_flush_worker(&priv->disp_thread.worker); > > > kthread_stop(priv->disp_thread.thread); > > > priv->disp_thread.thread = NULL; > > > @@ -474,9 +445,6 @@ static int msm_drm_init(struct device *dev, struct > > drm_driver *drv) > > > priv->wq = alloc_ordered_workqueue("msm", 0); > > > > > > INIT_LIST_HEAD(&priv->inactive_list); > > > - INIT_LIST_HEAD(&priv->vblank_ctrl.event_list); > > > - kthread_init_work(&priv->vblank_ctrl.work, vblank_ctrl_worker); > > > - spin_lock_init(&priv->vblank_ctrl.lock); > > > > > > drm_mode_config_init(ddev); > > > > > > diff --git a/drivers/gpu/drm/msm/msm_drv.h > > b/drivers/gpu/drm/msm/msm_drv.h > > > index e81b1fa..b91e306 100644 > > > --- a/drivers/gpu/drm/msm/msm_drv.h > > > +++ b/drivers/gpu/drm/msm/msm_drv.h > > > @@ -77,12 +77,6 @@ enum msm_mdp_plane_property { > > > PLANE_PROP_MAX_NUM > > > }; > > > > > > -struct msm_vblank_ctrl { > > > - struct kthread_work work; > > > - struct list_head event_list; > > > - spinlock_t lock; > > > -}; > > > - > > > #define MSM_GPU_MAX_RINGS 4 > > > #define MAX_H_TILES_PER_DISPLAY 2 > > > > > > @@ -226,7 +220,6 @@ struct msm_drm_private { > > > struct notifier_block vmap_notifier; > > > struct shrinker shrinker; > > > > > > - struct msm_vblank_ctrl vblank_ctrl; > > > struct drm_atomic_state *pm_state; > > > }; > > > > > > -- > > > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora > > Forum, > > > a Linux Foundation Collaborative Project > > > > > > _______________________________________________ > > > Freedreno mailing list > > > Freedreno@xxxxxxxxxxxxxxxxxxxxx > > > https://lists.freedesktop.org/mailman/listinfo/freedreno > > -- > Jeykumar S -- Sean Paul, Software Engineer, Google / Chromium OS _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel