[PATCH 1/7] drm/msm: move wq handling to KMS code

[Rob Clark]

On Sun, Apr 13, 2025 at 9:33 AM Dmitry Baryshkov
<dmitry.baryshkov at oss.qualcomm.com> wrote:
>
> The global workqueue is only used for vblanks inside KMS code. Move
> allocation / flushing / deallcation of it to msm_kms.c

Maybe we should also just move the wq into struct msm_kms?

BR,
-R

>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at oss.qualcomm.com>
> ---
>  drivers/gpu/drm/msm/msm_drv.c | 21 ++-------------------
>  drivers/gpu/drm/msm/msm_kms.c | 16 +++++++++++++++-
>  2 files changed, 17 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index c3588dc9e53764a27efda1901b094724cec8928a..02beb40eb9146941aa43862d07a6d82ae21c965e 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -82,13 +82,6 @@ static int msm_drm_uninit(struct device *dev)
>                         drm_atomic_helper_shutdown(ddev);
>         }
>
> -       /* We must cancel and cleanup any pending vblank enable/disable
> -        * work before msm_irq_uninstall() to avoid work re-enabling an
> -        * irq after uninstall has disabled it.
> -        */
> -
> -       flush_workqueue(priv->wq);
> -
>         msm_gem_shrinker_cleanup(ddev);
>
>         msm_perf_debugfs_cleanup(priv);
> @@ -104,8 +97,6 @@ static int msm_drm_uninit(struct device *dev)
>         ddev->dev_private = NULL;
>         drm_dev_put(ddev);
>
> -       destroy_workqueue(priv->wq);
> -
>         return 0;
>  }
>
> @@ -227,12 +218,6 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>         ddev->dev_private = priv;
>         priv->dev = ddev;
>
> -       priv->wq = alloc_ordered_workqueue("msm", 0);
> -       if (!priv->wq) {
> -               ret = -ENOMEM;
> -               goto err_put_dev;
> -       }
> -
>         INIT_LIST_HEAD(&priv->objects);
>         mutex_init(&priv->obj_lock);
>
> @@ -253,12 +238,12 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>         if (priv->kms_init) {
>                 ret = drmm_mode_config_init(ddev);
>                 if (ret)
> -                       goto err_destroy_wq;
> +                       goto err_put_dev;
>         }
>
>         ret = msm_init_vram(ddev);
>         if (ret)
> -               goto err_destroy_wq;
> +               goto err_put_dev;
>
>         dma_set_max_seg_size(dev, UINT_MAX);
>
> @@ -304,8 +289,6 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>
>  err_deinit_vram:
>         msm_deinit_vram(ddev);
> -err_destroy_wq:
> -       destroy_workqueue(priv->wq);
>  err_put_dev:
>         drm_dev_put(ddev);
>
> diff --git a/drivers/gpu/drm/msm/msm_kms.c b/drivers/gpu/drm/msm/msm_kms.c
> index 35d5397e73b4c5cb90b1770e8570277e782be7ec..821f0b9f968fc3d448e612bfae04639ceb770353 100644
> --- a/drivers/gpu/drm/msm/msm_kms.c
> +++ b/drivers/gpu/drm/msm/msm_kms.c
> @@ -227,6 +227,13 @@ void msm_drm_kms_uninit(struct device *dev)
>
>         BUG_ON(!kms);
>
> +       /* We must cancel and cleanup any pending vblank enable/disable
> +        * work before msm_irq_uninstall() to avoid work re-enabling an
> +        * irq after uninstall has disabled it.
> +        */
> +
> +       flush_workqueue(priv->wq);
> +
>         /* clean up event worker threads */
>         for (i = 0; i < priv->num_crtcs; i++) {
>                 if (priv->event_thread[i].worker)
> @@ -243,6 +250,8 @@ void msm_drm_kms_uninit(struct device *dev)
>
>         if (kms && kms->funcs)
>                 kms->funcs->destroy(kms);
> +
> +       destroy_workqueue(priv->wq);
>  }
>
>  int msm_drm_kms_init(struct device *dev, const struct drm_driver *drv)
> @@ -258,10 +267,14 @@ int msm_drm_kms_init(struct device *dev, const struct drm_driver *drv)
>         if (ret)
>                 return ret;
>
> +       priv->wq = alloc_ordered_workqueue("msm", 0);
> +       if (!priv->wq)
> +               return -ENOMEM;
> +
>         ret = priv->kms_init(ddev);
>         if (ret) {
>                 DRM_DEV_ERROR(dev, "failed to load kms\n");
> -               return ret;
> +               goto err_msm_uninit;
>         }
>
>         /* Enable normalization of plane zpos */
> @@ -319,6 +332,7 @@ int msm_drm_kms_init(struct device *dev, const struct drm_driver *drv)
>         return 0;
>
>  err_msm_uninit:
> +       destroy_workqueue(priv->wq);
>         return ret;
>  }
>
>
> --
> 2.39.5
>