Re: [PATCH] drm/msm: validate display and event threads

[Abhinav Kumar <abhinavk@xxxxxxxxxxxxxx>]

On 2018-10-05 12:49, Jeykumar Sankaran wrote:
> While creating display and event threads per crtc, validate
> them before setting their priorities.
>
> Change-Id: I1dda805286df981c0f0e2b26507d089d3a21ff6c
> Signed-off-by: Jeykumar Sankaran <jsanka@xxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/msm_drv.c | 49 
> ++++++++++++++-----------------------------
>  1 file changed, 16 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.c 
> b/drivers/gpu/drm/msm/msm_drv.c
> index c1abad8..e03c659 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -553,17 +553,18 @@ static int msm_drm_init(struct device *dev,
> struct drm_driver *drv)
>  			kthread_run(kthread_worker_fn,
>  				&priv->disp_thread[i].worker,
>  				"crtc_commit:%d", priv->disp_thread[i].crtc_id);
> -		ret = sched_setscheduler(priv->disp_thread[i].thread,
> -							SCHED_FIFO, &param);
> -		if (ret)
> -			pr_warn("display thread priority update failed: %d\n",
> -									ret);
> -
>  		if (IS_ERR(priv->disp_thread[i].thread)) {
>  			dev_err(dev, "failed to create crtc_commit kthread\n");
>  			priv->disp_thread[i].thread = NULL;
> +			goto err_msm_uninit;
>  		}
>
> +		ret = sched_setscheduler(priv->disp_thread[i].thread,
> +					 SCHED_FIFO, &param);
> +		if (ret)
> +			pr_warn("display thread priority update failed: %d\n",
> +				ret);
dev_warn is better
> +
>  		/* initialize event thread */
>  		priv->event_thread[i].crtc_id = priv->crtcs[i]->base.id;
>  		kthread_init_worker(&priv->event_thread[i].worker);
> @@ -572,6 +573,12 @@ static int msm_drm_init(struct device *dev,
> struct drm_driver *drv)
>  			kthread_run(kthread_worker_fn,
>  				&priv->event_thread[i].worker,
>  				"crtc_event:%d", priv->event_thread[i].crtc_id);
> +		if (IS_ERR(priv->event_thread[i].thread)) {
> +			dev_err(dev, "failed to create crtc_event kthread\n");
> +			priv->event_thread[i].thread = NULL;
> +			goto err_msm_uninit;
> +		}
> +
>  		/**
>  		 * event thread should also run at same priority as disp_thread
>  		 * because it is handling frame_done events. A lower priority
> @@ -580,34 +587,10 @@ static int msm_drm_init(struct device *dev,
> struct drm_driver *drv)
>  		 * failure at crtc commit level.
>  		 */
>  		ret = sched_setscheduler(priv->event_thread[i].thread,
> -							SCHED_FIFO, &param);
> +					 SCHED_FIFO, &param);
>  		if (ret)
> -			pr_warn("display event thread priority update failed: %d\n",
> -									ret);
same as above
> -
> -		if (IS_ERR(priv->event_thread[i].thread)) {
> -			dev_err(dev, "failed to create crtc_event kthread\n");
> -			priv->event_thread[i].thread = NULL;
> -		}
> -
> -		if ((!priv->disp_thread[i].thread) ||
> -				!priv->event_thread[i].thread) {
> -			/* clean up previously created threads if any */
> -			for ( ; i >= 0; i--) {
> -				if (priv->disp_thread[i].thread) {
> -					kthread_stop(
> -						priv->disp_thread[i].thread);
> -					priv->disp_thread[i].thread = NULL;
> -				}
> -
> -				if (priv->event_thread[i].thread) {
> -					kthread_stop(
> -						priv->event_thread[i].thread);
> -					priv->event_thread[i].thread = NULL;
> -				}
> -			}
> -			goto err_msm_uninit;
> -		}
> +			pr_warn("display event thread priority update failed:%d\n",
> +				ret);
>  	}
same here
>  	ret = drm_vblank_init(ddev, priv->num_crtcs);