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

[Abhinav Kumar]

On 4/15/2025 1:59 AM, Dmitry Baryshkov wrote:

On 14/04/2025 18:58, Rob Clark wrote:

On Sun, Apr 13, 2025 at 9:33 AM Dmitry Baryshkov
<dmitry.barysh...@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?

... together with several other KMS-only fields. I will take a look.

Yeah the usages seem to be only within kms, so we can move this to msm_kms.

BR,
-R

Signed-off-by: Dmitry Baryshkov <dmitry.barysh...@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;
  }


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2.39.5