4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Daniel Vetter daniel.vetter@ffwll.ch
[ Upstream commit 5117bd898e8c0a31e8ab3a9b8523aecf0706e997 ]
- None of the list walkings where protected.
- Switch to a mutex since the list walking at device resume time can sleep when pinning buffers through the tiler.
Only thing we need to be careful with here is that while we walk the list we can't unreference any gem objects, since the final unref would result in a recursive deadlock. But the only functions that walk the list is the device resume and debugfs dumping, so all safe.
Signed-off-by: Daniel Vetter daniel.vetter@intel.com Reviewed-by: Tomi Valkeinen tomi.valkeinen@ti.com Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/omapdrm/omap_debugfs.c | 2 ++ drivers/gpu/drm/omapdrm/omap_drv.c | 2 +- drivers/gpu/drm/omapdrm/omap_drv.h | 2 +- drivers/gpu/drm/omapdrm/omap_gem.c | 15 +++++++++------ 4 files changed, 13 insertions(+), 8 deletions(-)
--- a/drivers/gpu/drm/omapdrm/omap_debugfs.c +++ b/drivers/gpu/drm/omapdrm/omap_debugfs.c @@ -37,7 +37,9 @@ static int gem_show(struct seq_file *m, return ret;
seq_printf(m, "All Objects:\n"); + mutex_lock(&priv->list_lock); omap_gem_describe_objects(&priv->obj_list, m); + mutex_unlock(&priv->list_lock);
mutex_unlock(&dev->struct_mutex);
--- a/drivers/gpu/drm/omapdrm/omap_drv.c +++ b/drivers/gpu/drm/omapdrm/omap_drv.c @@ -540,7 +540,7 @@ static int omapdrm_init(struct omap_drm_ priv->omaprev = soc ? (unsigned int)soc->data : 0; priv->wq = alloc_ordered_workqueue("omapdrm", 0);
- spin_lock_init(&priv->list_lock); + mutex_init(&priv->list_lock); INIT_LIST_HEAD(&priv->obj_list);
/* Allocate and initialize the DRM device. */ --- a/drivers/gpu/drm/omapdrm/omap_drv.h +++ b/drivers/gpu/drm/omapdrm/omap_drv.h @@ -71,7 +71,7 @@ struct omap_drm_private { struct workqueue_struct *wq;
/* lock for obj_list below */ - spinlock_t list_lock; + struct mutex list_lock;
/* list of GEM objects: */ struct list_head obj_list; --- a/drivers/gpu/drm/omapdrm/omap_gem.c +++ b/drivers/gpu/drm/omapdrm/omap_gem.c @@ -1001,6 +1001,7 @@ int omap_gem_resume(struct drm_device *d struct omap_gem_object *omap_obj; int ret = 0;
+ mutex_lock(&priv->list_lock); list_for_each_entry(omap_obj, &priv->obj_list, mm_list) { if (omap_obj->block) { struct drm_gem_object *obj = &omap_obj->base; @@ -1012,12 +1013,14 @@ int omap_gem_resume(struct drm_device *d omap_obj->roll, true); if (ret) { dev_err(dev->dev, "could not repin: %d\n", ret); - return ret; + goto done; } } }
- return 0; +done: + mutex_unlock(&priv->list_lock); + return ret; } #endif
@@ -1085,9 +1088,9 @@ void omap_gem_free_object(struct drm_gem
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
- spin_lock(&priv->list_lock); + mutex_lock(&priv->list_lock); list_del(&omap_obj->mm_list); - spin_unlock(&priv->list_lock); + mutex_unlock(&priv->list_lock);
/* this means the object is still pinned.. which really should * not happen. I think.. @@ -1206,9 +1209,9 @@ struct drm_gem_object *omap_gem_new(stru goto err_release; }
- spin_lock(&priv->list_lock); + mutex_lock(&priv->list_lock); list_add(&omap_obj->mm_list, &priv->obj_list); - spin_unlock(&priv->list_lock); + mutex_unlock(&priv->list_lock);
return obj;