[Intel-gfx] drm/i915/display: Fix warning callstack for imbalance wakeref

[Imre Deak]

On Mon, 29 Aug 2022 14:01:24 +0530, Mitul Golani wrote:
> While executing i915_selftest, wakeref imbalance warning is seen
> with i915_selftest failure.
> 
> Currently when Driver is suspended, while doing unregister
> it is taking wakeref without resuming the device.
> This patch is resuming the device, if driver is already suspended
> and doing unregister process. It will check the suspend state and
> if driver is not resumed before taking wakeref then resume before
> it.
> 
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_driver.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index 1332c70370a6..281bf6cd5e4c 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -953,7 +953,11 @@ int i915_driver_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  
>  void i915_driver_remove(struct drm_i915_private *i915)
>  {
> -	disable_rpm_wakeref_asserts(&i915->runtime_pm);
> +	intel_wakeref_t wakeref = 0;

Initing wakeref right before assigning to it is redundant.

> +	/*
> +	 * Resuming Device if already suspended to complete driver unregistration
> +	 */

No need for the above comment, which the function name makes clear
already.

> +	wakeref = intel_runtime_pm_get(&i915->runtime_pm);
>  
>  	i915_driver_unregister(i915);
>  
> @@ -977,18 +981,20 @@ void i915_driver_remove(struct drm_i915_private *i915)
>  
>  	i915_driver_hw_remove(i915);
>  
> -	enable_rpm_wakeref_asserts(&i915->runtime_pm);
> +	if (wakeref)
> +		intel_runtime_pm_put(&i915->runtime_pm, wakeref);

wakeref can't be 0, so the call can be unconditional.

>  }
>  
>  static void i915_driver_release(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(dev);
>  	struct intel_runtime_pm *rpm = &dev_priv->runtime_pm;
> +	intel_wakeref_t wakeref = 0;
>  
>  	if (!dev_priv->do_release)
>  		return;
>  
> -	disable_rpm_wakeref_asserts(rpm);
> +	wakeref = intel_runtime_pm_get(rpm);
>  
>  	i915_gem_driver_release(dev_priv);
>  
> @@ -999,7 +1005,9 @@ static void i915_driver_release(struct drm_device *dev)
>  
>  	i915_driver_mmio_release(dev_priv);
>  
> -	enable_rpm_wakeref_asserts(rpm);
> +	if (wakeref)
> +		intel_runtime_pm_put(rpm, wakeref);
> +
>  	intel_runtime_pm_driver_release(rpm);
>  
>  	i915_driver_late_release(dev_priv);