Re: [PATCH v2 3/3] drm/tegra: Implement subsystem-level suspend/resume

[Daniel Vetter <daniel@ffwll.ch>]

On Wed, Aug 12, 2015 at 04:37:30PM +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Use the drm_atomic_helper_suspend() and drm_atomic_helper_resume()
> helpers to implement subsystem-level suspend/resume.
> 
> v2: suspend framebuffer device to avoid concurrency issues
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/gpu/drm/tegra/drm.c | 11 +++++++++++
>  drivers/gpu/drm/tegra/drm.h |  4 ++++
>  drivers/gpu/drm/tegra/fb.c  | 24 ++++++++++++++++++++++++
>  3 files changed, 39 insertions(+)
> 
> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
> index b5f24c0f93dc..10d62e3077de 100644
> --- a/drivers/gpu/drm/tegra/drm.c
> +++ b/drivers/gpu/drm/tegra/drm.c
> @@ -1022,8 +1022,16 @@ static int host1x_drm_remove(struct host1x_device *dev)
>  static int host1x_drm_suspend(struct device *dev)
>  {
>  	struct drm_device *drm = dev_get_drvdata(dev);
> +	struct tegra_drm *tegra = drm->dev_private;
>  
>  	drm_kms_helper_poll_disable(drm);
> +	tegra_drm_fb_suspend(drm);
> +
> +	tegra->state = drm_atomic_helper_suspend(drm);
> +	if (IS_ERR(tegra->state)) {
> +		drm_kms_helper_poll_enable(drm);
> +		return PTR_ERR(tegra->state);
> +	}
>  
>  	return 0;
>  }
> @@ -1031,7 +1039,10 @@ static int host1x_drm_suspend(struct device *dev)
>  static int host1x_drm_resume(struct device *dev)
>  {
>  	struct drm_device *drm = dev_get_drvdata(dev);
> +	struct tegra_drm *tegra = drm->dev_private;
>  
> +	drm_atomic_helper_resume(drm, tegra->state);
> +	tegra_drm_fb_resume(drm);
>  	drm_kms_helper_poll_enable(drm);
>  
>  	return 0;
> diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
> index 567831191f8b..112e07d81557 100644
> --- a/drivers/gpu/drm/tegra/drm.h
> +++ b/drivers/gpu/drm/tegra/drm.h
> @@ -57,6 +57,8 @@ struct tegra_drm {
>  		struct work_struct work;
>  		struct mutex lock;
>  	} commit;
> +
> +	struct drm_atomic_state *state;
>  };
>  
>  struct tegra_drm_client;
> @@ -267,6 +269,8 @@ int tegra_drm_fb_prepare(struct drm_device *drm);
>  void tegra_drm_fb_free(struct drm_device *drm);
>  int tegra_drm_fb_init(struct drm_device *drm);
>  void tegra_drm_fb_exit(struct drm_device *drm);
> +void tegra_drm_fb_suspend(struct drm_device *drm);
> +void tegra_drm_fb_resume(struct drm_device *drm);
>  #ifdef CONFIG_DRM_FBDEV_EMULATION
>  void tegra_fbdev_restore_mode(struct tegra_fbdev *fbdev);
>  void tegra_fb_output_poll_changed(struct drm_device *drm);
> diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
> index 9b8aa967fa71..6c60795a2622 100644
> --- a/drivers/gpu/drm/tegra/fb.c
> +++ b/drivers/gpu/drm/tegra/fb.c
> @@ -10,6 +10,8 @@
>   * published by the Free Software Foundation.
>   */
>  
> +#include <linux/console.h>
> +
>  #include "drm.h"
>  #include "gem.h"
>  
> @@ -414,3 +416,25 @@ void tegra_drm_fb_exit(struct drm_device *drm)
>  	tegra_fbdev_exit(tegra->fbdev);
>  #endif
>  }
> +
> +void tegra_drm_fb_suspend(struct drm_device *drm)
> +{
> +#ifdef CONFIG_DRM_FBDEV_EMULATION
> +	struct tegra_drm *tegra = drm->dev_private;
> +
> +	console_lock();
> +	drm_fb_helper_set_suspend(&tegra->fbdev->base, 1);
> +	console_unlock();
> +#endif

Should we move console_lock/unlock into the helper to avoid ugly ifdefery
like here? Just an aside really. We would need an _unlocked version then
though for i915, which tries to avoid the console_lock overhead with a
trylock and async worker. Or we could just move this into the fbdev helper
library too.
-Daniel

> +}
> +
> +void tegra_drm_fb_resume(struct drm_device *drm)
> +{
> +#ifdef CONFIG_DRM_FBDEV_EMULATION
> +	struct tegra_drm *tegra = drm->dev_private;
> +
> +	console_lock();
> +	drm_fb_helper_set_suspend(&tegra->fbdev->base, 0);
> +	console_unlock();
> +#endif
> +}
> -- 
> 2.4.5
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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