[Intel-gfx] [PATCH 1/2] drm/i915: Try harder to reset the GPU

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> Repeat the reset a couple of times if at first we do not succeed.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Link:
> http://patchwork.freedesktop.org/patch/msgid/20170513083726.502-1-chris@chris-wilson.co.uk

Seems that this is already merged but FWIW.

Reviewed-by: Mika Kuoppala <mika.kuoppala at intel.com>

> ---
>  drivers/gpu/drm/i915/intel_uncore.c | 44 +++++++++++++++++++++----------------
>  1 file changed, 25 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index 71b9b387ad04..fc3da0a6fdbb 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -1463,9 +1463,10 @@ int i915_reg_read_ioctl(struct drm_device *dev,
>  	return ret;
>  }
>  
> -static int i915_reset_complete(struct pci_dev *pdev)
> +static bool i915_reset_complete(struct pci_dev *pdev)
>  {
>  	u8 gdrst;
> +
>  	pci_read_config_byte(pdev, I915_GDRST, &gdrst);
>  	return (gdrst & GRDOM_RESET_STATUS) == 0;
>  }
> @@ -1476,15 +1477,16 @@ static int i915_do_reset(struct drm_i915_private *dev_priv, unsigned engine_mask
>  
>  	/* assert reset for at least 20 usec */
>  	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
> -	udelay(20);
> +	usleep_range(50, 200);
>  	pci_write_config_byte(pdev, I915_GDRST, 0);
>  
>  	return wait_for(i915_reset_complete(pdev), 500);
>  }
>  
> -static int g4x_reset_complete(struct pci_dev *pdev)
> +static bool g4x_reset_complete(struct pci_dev *pdev)
>  {
>  	u8 gdrst;
> +
>  	pci_read_config_byte(pdev, I915_GDRST, &gdrst);
>  	return (gdrst & GRDOM_RESET_ENABLE) == 0;
>  }
> @@ -1492,6 +1494,7 @@ static int g4x_reset_complete(struct pci_dev *pdev)
>  static int g33_do_reset(struct drm_i915_private *dev_priv, unsigned engine_mask)
>  {
>  	struct pci_dev *pdev = dev_priv->drm.pdev;
> +
>  	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
>  	return wait_for(g4x_reset_complete(pdev), 500);
>  }
> @@ -1505,7 +1508,7 @@ static int g4x_do_reset(struct drm_i915_private *dev_priv, unsigned engine_mask)
>  			      GRDOM_RENDER | GRDOM_RESET_ENABLE);
>  	ret =  wait_for(g4x_reset_complete(pdev), 500);
>  	if (ret)
> -		return ret;
> +		goto out;
>  
>  	/* WaVcpClkGateDisableForMediaReset:ctg,elk */
>  	I915_WRITE(VDECCLK_GATE_D, I915_READ(VDECCLK_GATE_D) | VCP_UNIT_CLOCK_GATE_DISABLE);
> @@ -1514,16 +1517,14 @@ static int g4x_do_reset(struct drm_i915_private *dev_priv, unsigned engine_mask)
>  	pci_write_config_byte(pdev, I915_GDRST,
>  			      GRDOM_MEDIA | GRDOM_RESET_ENABLE);
>  	ret =  wait_for(g4x_reset_complete(pdev), 500);
> -	if (ret)
> -		return ret;
>  
>  	/* WaVcpClkGateDisableForMediaReset:ctg,elk */
>  	I915_WRITE(VDECCLK_GATE_D, I915_READ(VDECCLK_GATE_D) & ~VCP_UNIT_CLOCK_GATE_DISABLE);
>  	POSTING_READ(VDECCLK_GATE_D);
>  
> +out:
>  	pci_write_config_byte(pdev, I915_GDRST, 0);
> -
> -	return 0;
> +	return ret;
>  }
>  
>  static int ironlake_do_reset(struct drm_i915_private *dev_priv,
> @@ -1531,25 +1532,21 @@ static int ironlake_do_reset(struct drm_i915_private *dev_priv,
>  {
>  	int ret;
>  
> -	I915_WRITE(ILK_GDSR,
> -		   ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE);
> +	I915_WRITE(ILK_GDSR, ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE);
>  	ret = intel_wait_for_register(dev_priv,
>  				      ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0,
>  				      500);
>  	if (ret)
> -		return ret;
> +		goto out;
>  
> -	I915_WRITE(ILK_GDSR,
> -		   ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE);
> +	I915_WRITE(ILK_GDSR, ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE);
>  	ret = intel_wait_for_register(dev_priv,
>  				      ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0,
>  				      500);
> -	if (ret)
> -		return ret;
> -
> +out:
>  	I915_WRITE(ILK_GDSR, 0);
> -
> -	return 0;
> +	POSTING_READ(ILK_GDSR);
> +	return ret;
>  }
>  
>  /* Reset the hardware domains (GENX_GRDOM_*) specified by mask */
> @@ -1758,8 +1755,11 @@ static reset_func intel_get_gpu_reset(struct drm_i915_private *dev_priv)
>  int intel_gpu_reset(struct drm_i915_private *dev_priv, unsigned engine_mask)
>  {
>  	reset_func reset;
> +	int retry;
>  	int ret;
>  
> +	might_sleep();
> +
>  	reset = intel_get_gpu_reset(dev_priv);
>  	if (reset == NULL)
>  		return -ENODEV;
> @@ -1768,7 +1768,13 @@ int intel_gpu_reset(struct drm_i915_private *dev_priv, unsigned engine_mask)
>  	 * request may be dropped and never completes (causing -EIO).
>  	 */
>  	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
> -	ret = reset(dev_priv, engine_mask);
> +	for (retry = 0; retry < 3; retry++) {
> +		ret = reset(dev_priv, engine_mask);
> +		if (ret != -ETIMEDOUT)
> +			break;
> +
> +		cond_resched();
> +	}
>  	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
>  
>  	return ret;
> -- 
> 2.11.0
>
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