Hi Roland,
Hopefully you had a nice start into the new year! Ping for some
review/testing on this series.
Thanks, Daniel
On Fri, Dec 11, 2020 at 5:29 PM Daniel Vetter <daniel.vetter@xxxxxxxx> wrote:
>
> This isn't actually protecting anything becuase:
> - when running, ttm_resource_manager->use_type is protected through
> vmw_private->reservation_semaphore against concurrent execbuf or
> well anything else that might evict or reserve buffers
> - during suspend/resume there's nothing else running, hence
> vmw_pm_freeze and vmw_pm_restore do not need to take the same lock.
> - this also holds for the SVGA_REG_ENABLE register write
>
> Hence it is safe to just remove that spinlock.
>
> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> Cc: VMware Graphics <linux-graphics-maintainer@xxxxxxxxxx>
> Cc: Roland Scheidegger <sroland@xxxxxxxxxx>
> ---
> drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 10 +---------
> drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 1 -
> 2 files changed, 1 insertion(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> index 0008be02d31c..204f7a1830f0 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> @@ -672,7 +672,6 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
> spin_lock_init(&dev_priv->hw_lock);
> spin_lock_init(&dev_priv->waiter_lock);
> spin_lock_init(&dev_priv->cap_lock);
> - spin_lock_init(&dev_priv->svga_lock);
> spin_lock_init(&dev_priv->cursor_lock);
>
> for (i = vmw_res_context; i < vmw_res_max; ++i) {
> @@ -1189,12 +1188,10 @@ static void __vmw_svga_enable(struct vmw_private *dev_priv)
> {
> struct ttm_resource_manager *man = ttm_manager_type(&dev_priv->bdev, TTM_PL_VRAM);
>
> - spin_lock(&dev_priv->svga_lock);
> if (!ttm_resource_manager_used(man)) {
> vmw_write(dev_priv, SVGA_REG_ENABLE, SVGA_REG_ENABLE);
> ttm_resource_manager_set_used(man, true);
> }
> - spin_unlock(&dev_priv->svga_lock);
> }
>
> /**
> @@ -1220,14 +1217,12 @@ static void __vmw_svga_disable(struct vmw_private *dev_priv)
> {
> struct ttm_resource_manager *man = ttm_manager_type(&dev_priv->bdev, TTM_PL_VRAM);
>
> - spin_lock(&dev_priv->svga_lock);
> if (ttm_resource_manager_used(man)) {
> ttm_resource_manager_set_used(man, false);
> vmw_write(dev_priv, SVGA_REG_ENABLE,
> SVGA_REG_ENABLE_HIDE |
> SVGA_REG_ENABLE_ENABLE);
> }
> - spin_unlock(&dev_priv->svga_lock);
> }
>
> /**
> @@ -1254,17 +1249,14 @@ void vmw_svga_disable(struct vmw_private *dev_priv)
> */
> vmw_kms_lost_device(dev_priv->dev);
> ttm_write_lock(&dev_priv->reservation_sem, false);
> - spin_lock(&dev_priv->svga_lock);
> if (ttm_resource_manager_used(man)) {
> ttm_resource_manager_set_used(man, false);
> - spin_unlock(&dev_priv->svga_lock);
> if (ttm_resource_manager_evict_all(&dev_priv->bdev, man))
> DRM_ERROR("Failed evicting VRAM buffers.\n");
> vmw_write(dev_priv, SVGA_REG_ENABLE,
> SVGA_REG_ENABLE_HIDE |
> SVGA_REG_ENABLE_ENABLE);
> - } else
> - spin_unlock(&dev_priv->svga_lock);
> + }
> ttm_write_unlock(&dev_priv->reservation_sem);
> }
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> index 5b9a28157dd3..715f2bfee08a 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> @@ -596,7 +596,6 @@ struct vmw_private {
>
> bool stealth;
> bool enable_fb;
> - spinlock_t svga_lock;
>
> /**
> * PM management.
> --
> 2.29.2
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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