RFC: Add drm_dev_suspend/resume() ?

Noralf Trønnes noralf at tronnes.org
Wed Nov 1 12:59:00 UTC 2017


Den 01.11.2017 09.47, skrev Daniel Vetter:
> On Tue, Oct 31, 2017 at 05:37:23PM +0100, Noralf Trønnes wrote:
>> Den 30.10.2017 10.34, skrev Daniel Vetter:
>>> Hi Noralf,
>>>
>>> On Sun, Oct 22, 2017 at 06:52:41PM +0200, Noralf Trønnes wrote:
>>>> Hi,
>>>>
>>>> I've spent some time in the fbdev emulation code and discovered a
>>>> recurring pattern around suspend/resume.
>>>> Should we add some more helpers :-)
>>> You're maybe a bit too good at spotting these for your own good :-)
>>>
>>> But yeah, a "suspend for dummies" is one of the things which would be nice
>>> I think ... Especially since we now have the atomic suspend/resume
>>> helpers.
>>>
>>>> struct drm_device {
>>>>       /**
>>>>        * @suspend_state:
>>>>        *
>>>>        * Atomic state when suspended.
>>>>        * Set by drm_dev_suspend(), cleared by drm_dev_resume().
>>>>        */
>>>>       struct drm_atomic_state *suspend_state;
>>>> };
>>> Imo fits better when we put it into drm_mode_config.
>>>
>>>> int drm_dev_suspend(struct drm_device *dev)
>>>> {
>>>>       struct drm_atomic_state *state;
>>>>
>>>>       if (!dev)
>>>>           return 0;
>>>>
>>>>       drm_kms_helper_poll_disable(dev);
>>>>       drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 1);
>>>>       state = drm_atomic_helper_suspend(dev);
>>>>       if (IS_ERR(state)) {
>>>>           drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
>>>>           drm_kms_helper_poll_enable(dev);
>>>>           return PTR_ERR(state);
>>>>       }
>>>>
>>>>       dev->suspend_state = state;
>>>>
>>>>       return 0;
>>>> }
>>> This is all about suspending the modeset side ... I'd give it a
>>> drm_mode_config prefix instead of the drm_dev_ (that's maybe a bit too
>>> generic), but then maybe type a general suspend/resume kernel-doc text in
>>> the drm-internals.rst (maybe pulled in from drm_dev.c) which references
>>> these 2 functions as the recommended way to suspend/resume the modeset
>>> side of a driver. These won't suspend/resume a render part (if present),
>>> so drm_dev_ seems a bit too much.
>> I just realised that this is pulling helpers (atomic, crtc, fbdev) into
>> the core which IIRC is something that you didn't want?
> Ugh right. I think starting a new drm_mode_config_helper.c for top-level
> helper stuff would be a reasonable solution. Or some other name if you
> have a better one.

Does it fit in drm_modeset_helper.c ?

/**
  * DOC: aux kms helpers
  *
  * This helper library contains various one-off functions which don't 
really fit
  * anywhere else in the DRM modeset helper library.
  */

Noralf.

> -Daniel
>
>>
>> diff --git a/drivers/gpu/drm/drm_mode_config.c
>> b/drivers/gpu/drm/drm_mode_config.c
>> index 74f6ff5df656..72f8fe1e83cb 100644
>> --- a/drivers/gpu/drm/drm_mode_config.c
>> +++ b/drivers/gpu/drm/drm_mode_config.c
>> @@ -20,7 +20,10 @@
>>    * OF THIS SOFTWARE.
>>    */
>>
>> +#include <drm/drm_atomic_helper.h>
>> +#include <drm/drm_crtc_helper.h>
>>   #include <drm/drm_encoder.h>
>> +#include <drm/drm_fb_helper.h>
>>   #include <drm/drm_mode_config.h>
>>   #include <drm/drmP.h>
>>
>> @@ -473,3 +476,49 @@ void drm_mode_config_cleanup(struct drm_device *dev)
>> drm_modeset_lock_fini(&dev->mode_config.connection_mutex);
>>   }
>>   EXPORT_SYMBOL(drm_mode_config_cleanup);
>> +
>> +/**
>> + * drm_mode_config_suspend
>> + * @dev: DRM device
>> + *
>> + */
>> +int drm_mode_config_suspend(struct drm_device *dev)
>> +{
>> +       struct drm_atomic_state *state;
>> +
>> +       if (!dev)
>> +               return 0;
>> +
>> +       drm_kms_helper_poll_disable(dev);
>> +       drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 1);
>> +       state = drm_atomic_helper_suspend(dev);
>> +       if (IS_ERR(state)) {
>> + drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
>> +               drm_kms_helper_poll_enable(dev);
>> +               return PTR_ERR(state);
>> +       }
>> +
>> +       dev->mode_config.suspend_state = state;
>> +
>> +       return 0;
>> +}
>> +EXPORT_SYMBOL(drm_mode_config_suspend);
>> +
>> +int drm_mode_config_resume(struct drm_device *dev)
>> +{
>> +       int ret;
>> +
>> +       if (!dev || WARN_ON(!dev->mode_config.suspend_state))
>> +               return 0;
>> +
>> +       ret = drm_atomic_helper_resume(dev, dev->mode_config.suspend_state);
>> +       if (ret)
>> +               DRM_ERROR("Failed to resume (%d)\n", ret);
>> +       dev->mode_config.suspend_state = NULL;
>> +
>> +       drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
>> +       drm_kms_helper_poll_enable(dev);
>> +
>> +       return 0;
>> +}
>> +EXPORT_SYMBOL(drm_mode_config_resume);
>> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
>> index 1b37368416c8..86ef327a996d 100644
>> --- a/include/drm/drm_mode_config.h
>> +++ b/include/drm/drm_mode_config.h
>> @@ -766,11 +766,21 @@ struct drm_mode_config {
>>          /* cursor size */
>>          uint32_t cursor_width, cursor_height;
>>
>> +       /**
>> +        * @suspend_state:
>> +        *
>> +        * Atomic state when suspended. Set by drm_mode_config_suspend(),
>> +        * cleared by drm_mode_config_resume().
>> +        */
>> +       struct drm_atomic_state *suspend_state;
>> +
>>          const struct drm_mode_config_helper_funcs *helper_private;
>>   };
>>
>>   void drm_mode_config_init(struct drm_device *dev);
>>   void drm_mode_config_reset(struct drm_device *dev);
>>   void drm_mode_config_cleanup(struct drm_device *dev);
>> +int drm_mode_config_suspend(struct drm_device *dev);
>> +int drm_mode_config_resume(struct drm_device *dev);
>>
>>   #endif
>>
>>
>> Noralf.
>>
>>>> int drm_dev_resume(struct drm_device *dev)
>>>> {
>>>>       int ret;
>>>>
>>>>       if (!dev || WARN_ON(!dev->suspend_state))
>>>>           return 0;
>>>>
>>>>       ret = drm_atomic_helper_resume(dev, dev->suspend_state);
>>>>       if (ret)
>>>>           DRM_ERROR("Failed to resume (%d)\n", ret);
>>>>       dev->suspend_state = NULL;
>>>>
>>>>       drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
>>>>       drm_kms_helper_poll_enable(dev);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> The drm_kms_helper_poll_enable() docs states that it's not allowed to
>>>> call this function if polling support has been set up, but the code
>>>> allows it. drm_kms_helper_poll_disable() docs states that it's ok to
>>>> call it even if polling is not enabled.
>>> Yeah need to fix that, but need to keep a note that if you want polling,
>>> then you need to follow that order or it goes wrong. Perhaps explain that
>>> this is meant to avoid special-cases in suspend/resume code?
>>>
>>>> Here are the suspend/resume code from the drivers that use
>>>> drm_atomic_helper_suspend/resume():
>>> Yeah, looks like a really good idea.
>>>
>>> Thanks, Daniel
>>>> static int __maybe_unused hdlcd_pm_suspend(struct device *dev)
>>>> {
>>>>       struct drm_device *drm = dev_get_drvdata(dev);
>>>>       struct hdlcd_drm_private *hdlcd = drm ? drm->dev_private : NULL;
>>>>
>>>>       if (!hdlcd)
>>>>           return 0;
>>>>
>>>>       drm_kms_helper_poll_disable(drm);
>>>>
>>>>       hdlcd->state = drm_atomic_helper_suspend(drm);
>>>>       if (IS_ERR(hdlcd->state)) {
>>>>           drm_kms_helper_poll_enable(drm);
>>>>           return PTR_ERR(hdlcd->state);
>>>>       }
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> static int __maybe_unused hdlcd_pm_resume(struct device *dev)
>>>> {
>>>>       struct drm_device *drm = dev_get_drvdata(dev);
>>>>       struct hdlcd_drm_private *hdlcd = drm ? drm->dev_private : NULL;
>>>>
>>>>       if (!hdlcd)
>>>>           return 0;
>>>>
>>>>       drm_atomic_helper_resume(drm, hdlcd->state);
>>>>       drm_kms_helper_poll_enable(drm);
>>>>       pm_runtime_set_active(dev);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>>
>>>> static int __maybe_unused malidp_pm_suspend(struct device *dev)
>>>> {
>>>>       struct drm_device *drm = dev_get_drvdata(dev);
>>>>       struct malidp_drm *malidp = drm->dev_private;
>>>>
>>>>       drm_kms_helper_poll_disable(drm);
>>>>       console_lock();
>>>>       drm_fbdev_cma_set_suspend(malidp->fbdev, 1);
>>>>       console_unlock();
>>>>       malidp->pm_state = drm_atomic_helper_suspend(drm);
>>>>       if (IS_ERR(malidp->pm_state)) {
>>>>           console_lock();
>>>>           drm_fbdev_cma_set_suspend(malidp->fbdev, 0);
>>>>           console_unlock();
>>>>           drm_kms_helper_poll_enable(drm);
>>>>           return PTR_ERR(malidp->pm_state);
>>>>       }
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> static int __maybe_unused malidp_pm_resume(struct device *dev)
>>>> {
>>>>       struct drm_device *drm = dev_get_drvdata(dev);
>>>>       struct malidp_drm *malidp = drm->dev_private;
>>>>
>>>>       drm_atomic_helper_resume(drm, malidp->pm_state);
>>>>       console_lock();
>>>>       drm_fbdev_cma_set_suspend(malidp->fbdev, 0);
>>>>       console_unlock();
>>>>       drm_kms_helper_poll_enable(drm);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>>
>>>> static int atmel_hlcdc_dc_drm_suspend(struct device *dev)
>>>> {
>>>>       struct drm_device *drm_dev = dev_get_drvdata(dev);
>>>>       struct atmel_hlcdc_dc *dc = drm_dev->dev_private;
>>>>       struct regmap *regmap = dc->hlcdc->regmap;
>>>>       struct drm_atomic_state *state;
>>>>
>>>>       state = drm_atomic_helper_suspend(drm_dev);
>>>>       if (IS_ERR(state))
>>>>           return PTR_ERR(state);
>>>>
>>>>       dc->suspend.state = state;
>>>>
>>>>       regmap_read(regmap, ATMEL_HLCDC_IMR, &dc->suspend.imr);
>>>>       regmap_write(regmap, ATMEL_HLCDC_IDR, dc->suspend.imr);
>>>>       clk_disable_unprepare(dc->hlcdc->periph_clk);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> static int atmel_hlcdc_dc_drm_resume(struct device *dev)
>>>> {
>>>>       struct drm_device *drm_dev = dev_get_drvdata(dev);
>>>>       struct atmel_hlcdc_dc *dc = drm_dev->dev_private;
>>>>
>>>>       clk_prepare_enable(dc->hlcdc->periph_clk);
>>>>       regmap_write(dc->hlcdc->regmap, ATMEL_HLCDC_IER, dc->suspend.imr);
>>>>
>>>>       return drm_atomic_helper_resume(drm_dev, dc->suspend.state);
>>>> }
>>>>
>>>>
>>>> static int exynos_drm_suspend(struct device *dev)
>>>> {
>>>>       struct drm_device *drm_dev = dev_get_drvdata(dev);
>>>>       struct exynos_drm_private *private = drm_dev->dev_private;
>>>>
>>>>       if (pm_runtime_suspended(dev) || !drm_dev)
>>>>           return 0;
>>>>
>>>>       drm_kms_helper_poll_disable(drm_dev);
>>>>       exynos_drm_fbdev_suspend(drm_dev);
>>>>       private->suspend_state = drm_atomic_helper_suspend(drm_dev);
>>>>       if (IS_ERR(private->suspend_state)) {
>>>>           exynos_drm_fbdev_resume(drm_dev);
>>>>           drm_kms_helper_poll_enable(drm_dev);
>>>>           return PTR_ERR(private->suspend_state);
>>>>       }
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> static int exynos_drm_resume(struct device *dev)
>>>> {
>>>>       struct drm_device *drm_dev = dev_get_drvdata(dev);
>>>>       struct exynos_drm_private *private = drm_dev->dev_private;
>>>>
>>>>       if (pm_runtime_suspended(dev) || !drm_dev)
>>>>           return 0;
>>>>
>>>>       drm_atomic_helper_resume(drm_dev, private->suspend_state);
>>>>       exynos_drm_fbdev_resume(drm_dev);
>>>>       drm_kms_helper_poll_enable(drm_dev);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>>
>>>> static int fsl_dcu_drm_pm_suspend(struct device *dev)
>>>> {
>>>>       struct fsl_dcu_drm_device *fsl_dev = dev_get_drvdata(dev);
>>>>
>>>>       if (!fsl_dev)
>>>>           return 0;
>>>>
>>>>       disable_irq(fsl_dev->irq);
>>>>       drm_kms_helper_poll_disable(fsl_dev->drm);
>>>>
>>>>       console_lock();
>>>>       drm_fbdev_cma_set_suspend(fsl_dev->fbdev, 1);
>>>>       console_unlock();
>>>>
>>>>       fsl_dev->state = drm_atomic_helper_suspend(fsl_dev->drm);
>>>>       if (IS_ERR(fsl_dev->state)) {
>>>>           console_lock();
>>>>           drm_fbdev_cma_set_suspend(fsl_dev->fbdev, 0);
>>>>           console_unlock();
>>>>
>>>>           drm_kms_helper_poll_enable(fsl_dev->drm);
>>>>           enable_irq(fsl_dev->irq);
>>>>           return PTR_ERR(fsl_dev->state);
>>>>       }
>>>>
>>>>       clk_disable_unprepare(fsl_dev->pix_clk);
>>>>       clk_disable_unprepare(fsl_dev->clk);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> static int fsl_dcu_drm_pm_resume(struct device *dev)
>>>> {
>>>>       struct fsl_dcu_drm_device *fsl_dev = dev_get_drvdata(dev);
>>>>       int ret;
>>>>
>>>>       if (!fsl_dev)
>>>>           return 0;
>>>>
>>>>       ret = clk_prepare_enable(fsl_dev->clk);
>>>>       if (ret < 0) {
>>>>           dev_err(dev, "failed to enable dcu clk\n");
>>>>           return ret;
>>>>       }
>>>>
>>>>       if (fsl_dev->tcon)
>>>>           fsl_tcon_bypass_enable(fsl_dev->tcon);
>>>>       fsl_dcu_drm_init_planes(fsl_dev->drm);
>>>>       drm_atomic_helper_resume(fsl_dev->drm, fsl_dev->state);
>>>>
>>>>       console_lock();
>>>>       drm_fbdev_cma_set_suspend(fsl_dev->fbdev, 0);
>>>>       console_unlock();
>>>>
>>>>       drm_kms_helper_poll_enable(fsl_dev->drm);
>>>>       enable_irq(fsl_dev->irq);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>>
>>>> static int __maybe_unused hibmc_pm_suspend(struct device *dev)
>>>> {
>>>>       struct pci_dev *pdev = to_pci_dev(dev);
>>>>       struct drm_device *drm_dev = pci_get_drvdata(pdev);
>>>>       struct hibmc_drm_private *priv = drm_dev->dev_private;
>>>>
>>>>       drm_kms_helper_poll_disable(drm_dev);
>>>>       priv->suspend_state = drm_atomic_helper_suspend(drm_dev);
>>>>       if (IS_ERR(priv->suspend_state)) {
>>>>           DRM_ERROR("drm_atomic_helper_suspend failed: %ld\n",
>>>>                 PTR_ERR(priv->suspend_state));
>>>>           drm_kms_helper_poll_enable(drm_dev);
>>>>           return PTR_ERR(priv->suspend_state);
>>>>       }
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> static int  __maybe_unused hibmc_pm_resume(struct device *dev)
>>>> {
>>>>       struct pci_dev *pdev = to_pci_dev(dev);
>>>>       struct drm_device *drm_dev = pci_get_drvdata(pdev);
>>>>       struct hibmc_drm_private *priv = drm_dev->dev_private;
>>>>
>>>>       drm_atomic_helper_resume(drm_dev, priv->suspend_state);
>>>>       drm_kms_helper_poll_enable(drm_dev);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>>
>>>> i915 is excluded since it's rather complicated.
>>>>
>>>>
>>>> static int imx_drm_suspend(struct device *dev)
>>>> {
>>>>       struct drm_device *drm_dev = dev_get_drvdata(dev);
>>>>       struct imx_drm_device *imxdrm;
>>>>
>>>>       /* The drm_dev is NULL before .load hook is called */
>>>>       if (drm_dev == NULL)
>>>>           return 0;
>>>>
>>>>       drm_kms_helper_poll_disable(drm_dev);
>>>>
>>>>       imxdrm = drm_dev->dev_private;
>>>>       imxdrm->state = drm_atomic_helper_suspend(drm_dev);
>>>>       if (IS_ERR(imxdrm->state)) {
>>>>           drm_kms_helper_poll_enable(drm_dev);
>>>>           return PTR_ERR(imxdrm->state);
>>>>       }
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> static int imx_drm_resume(struct device *dev)
>>>> {
>>>>       struct drm_device *drm_dev = dev_get_drvdata(dev);
>>>>       struct imx_drm_device *imx_drm;
>>>>
>>>>       if (drm_dev == NULL)
>>>>           return 0;
>>>>
>>>>       imx_drm = drm_dev->dev_private;
>>>>       drm_atomic_helper_resume(drm_dev, imx_drm->state);
>>>>       drm_kms_helper_poll_enable(drm_dev);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>>
>>>> static int mtk_drm_sys_suspend(struct device *dev)
>>>> {
>>>>       struct mtk_drm_private *private = dev_get_drvdata(dev);
>>>>       struct drm_device *drm = private->drm;
>>>>
>>>>       drm_kms_helper_poll_disable(drm);
>>>>
>>>>       private->suspend_state = drm_atomic_helper_suspend(drm);
>>>>       if (IS_ERR(private->suspend_state)) {
>>>>           drm_kms_helper_poll_enable(drm);
>>>>           return PTR_ERR(private->suspend_state);
>>>>       }
>>>>
>>>>       DRM_DEBUG_DRIVER("mtk_drm_sys_suspend\n");
>>>>       return 0;
>>>> }
>>>>
>>>> static int mtk_drm_sys_resume(struct device *dev)
>>>> {
>>>>       struct mtk_drm_private *private = dev_get_drvdata(dev);
>>>>       struct drm_device *drm = private->drm;
>>>>
>>>>       drm_atomic_helper_resume(drm, private->suspend_state);
>>>>       drm_kms_helper_poll_enable(drm);
>>>>
>>>>       DRM_DEBUG_DRIVER("mtk_drm_sys_resume\n");
>>>>       return 0;
>>>> }
>>>>
>>>>
>>>> nouveau is also rather complicated.
>>>>
>>>>
>>>> static int rockchip_drm_sys_suspend(struct device *dev)
>>>> {
>>>>       struct drm_device *drm = dev_get_drvdata(dev);
>>>>       struct rockchip_drm_private *priv;
>>>>
>>>>       if (!drm)
>>>>           return 0;
>>>>
>>>>       drm_kms_helper_poll_disable(drm);
>>>>       rockchip_drm_fb_suspend(drm);
>>>>
>>>>       priv = drm->dev_private;
>>>>       priv->state = drm_atomic_helper_suspend(drm);
>>>>       if (IS_ERR(priv->state)) {
>>>>           rockchip_drm_fb_resume(drm);
>>>>           drm_kms_helper_poll_enable(drm);
>>>>           return PTR_ERR(priv->state);
>>>>       }
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> static int rockchip_drm_sys_resume(struct device *dev)
>>>> {
>>>>       struct drm_device *drm = dev_get_drvdata(dev);
>>>>       struct rockchip_drm_private *priv;
>>>>
>>>>       if (!drm)
>>>>           return 0;
>>>>
>>>>       priv = drm->dev_private;
>>>>       drm_atomic_helper_resume(drm, priv->state);
>>>>       rockchip_drm_fb_resume(drm);
>>>>       drm_kms_helper_poll_enable(drm);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>>
>>>> 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)) {
>>>>           tegra_drm_fb_resume(drm);
>>>>           drm_kms_helper_poll_enable(drm);
>>>>           return PTR_ERR(tegra->state);
>>>>       }
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> 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;
>>>> }
>>>>
>>>>
>>>> static int tilcdc_pm_suspend(struct device *dev)
>>>> {
>>>>       struct drm_device *ddev = dev_get_drvdata(dev);
>>>>       struct tilcdc_drm_private *priv = ddev->dev_private;
>>>>
>>>>       priv->saved_state = drm_atomic_helper_suspend(ddev);
>>>>
>>>>       /* Select sleep pin state */
>>>>       pinctrl_pm_select_sleep_state(dev);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> static int tilcdc_pm_resume(struct device *dev)
>>>> {
>>>>       struct drm_device *ddev = dev_get_drvdata(dev);
>>>>       struct tilcdc_drm_private *priv = ddev->dev_private;
>>>>       int ret = 0;
>>>>
>>>>       /* Select default pin state */
>>>>       pinctrl_pm_select_default_state(dev);
>>>>
>>>>       if (priv->saved_state)
>>>>           ret = drm_atomic_helper_resume(ddev, priv->saved_state);
>>>>
>>>>       return ret;
>>>> }
>>>>
>>>>
>>>> int tinydrm_suspend(struct tinydrm_device *tdev)
>>>> {
>>>>       struct drm_atomic_state *state;
>>>>
>>>>       if (tdev->suspend_state) {
>>>>           DRM_ERROR("Failed to suspend: state already set\n");
>>>>           return -EINVAL;
>>>>       }
>>>>
>>>>       drm_fbdev_cma_set_suspend_unlocked(tdev->fbdev_cma, 1);
>>>>       state = drm_atomic_helper_suspend(tdev->drm);
>>>>       if (IS_ERR(state)) {
>>>>           drm_fbdev_cma_set_suspend_unlocked(tdev->fbdev_cma, 0);
>>>>           return PTR_ERR(state);
>>>>       }
>>>>
>>>>       tdev->suspend_state = state;
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>> int tinydrm_resume(struct tinydrm_device *tdev)
>>>> {
>>>>       struct drm_atomic_state *state = tdev->suspend_state;
>>>>       int ret;
>>>>
>>>>       if (!state) {
>>>>           DRM_ERROR("Failed to resume: state is not set\n");
>>>>           return -EINVAL;
>>>>       }
>>>>
>>>>       tdev->suspend_state = NULL;
>>>>
>>>>       ret = drm_atomic_helper_resume(tdev->drm, state);
>>>>       if (ret) {
>>>>           DRM_ERROR("Error resuming state: %d\n", ret);
>>>>           return ret;
>>>>       }
>>>>
>>>>       drm_fbdev_cma_set_suspend_unlocked(tdev->fbdev_cma, 0);
>>>>
>>>>       return 0;
>>>> }
>>>>
>>>>
>>>> Noralf.
>>>>



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