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[2/9] drm/i915: check for the supported strides on HSW+ FBC

Message ID 1442254803-20043-2-git-send-email-paulo.r.zanoni@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Zanoni, Paulo R Sept. 14, 2015, 6:19 p.m. UTC
Don't allow FBC for cases where the spec says we can't FBC.

v2:
  - Just WARN_ON() the strides that should have been caught earlier
    (Daniel)
  - Make it a new function since I expect this to grow more.
v3:
  - Document which IGT test is exercised by this.
v4:
  - Implement the restrictions for gens 2-6 too (Ville).
  - Fix off-by-one mistake (Ville).

Testcase: igt/kms_frontbuffer_tracking/fbc-badstride
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h  |  1 +
 drivers/gpu/drm/i915/intel_fbc.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

Comments

Ville Syrjala Sept. 21, 2015, 1:43 p.m. UTC | #1
On Mon, Sep 14, 2015 at 03:19:56PM -0300, Paulo Zanoni wrote:
> Don't allow FBC for cases where the spec says we can't FBC.
> 
> v2:
>   - Just WARN_ON() the strides that should have been caught earlier
>     (Daniel)
>   - Make it a new function since I expect this to grow more.
> v3:
>   - Document which IGT test is exercised by this.
> v4:
>   - Implement the restrictions for gens 2-6 too (Ville).
>   - Fix off-by-one mistake (Ville).
> 
> Testcase: igt/kms_frontbuffer_tracking/fbc-badstride
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h  |  1 +
>  drivers/gpu/drm/i915/intel_fbc.c | 28 ++++++++++++++++++++++++++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 3bf8a9b..8cf2969 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -948,6 +948,7 @@ struct i915_fbc {
>  		FBC_CHIP_DEFAULT, /* disabled by default on this chip */
>  		FBC_ROTATION, /* rotation is not supported */
>  		FBC_IN_DBG_MASTER, /* kernel debugger is active */
> +		FBC_BAD_STRIDE, /* stride is not supported */
>  	} no_fbc_reason;
>  
>  	bool (*fbc_enabled)(struct drm_i915_private *dev_priv);
> diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
> index 9e42079..db38091 100644
> --- a/drivers/gpu/drm/i915/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/intel_fbc.c
> @@ -480,6 +480,8 @@ const char *intel_no_fbc_reason_str(enum no_fbc_reason reason)
>  		return "rotation unsupported";
>  	case FBC_IN_DBG_MASTER:
>  		return "Kernel debugger is active";
> +	case FBC_BAD_STRIDE:
> +		return "framebuffer stride not supported";
>  	default:
>  		MISSING_CASE(reason);
>  		return "unknown reason";
> @@ -671,6 +673,27 @@ static int intel_fbc_setup_cfb(struct drm_i915_private *dev_priv, int size,
>  	return intel_fbc_alloc_cfb(dev_priv, size, fb_cpp);
>  }
>  
> +static bool stride_is_valid(struct drm_i915_private *dev_priv,
> +			    unsigned int stride)
> +{
> +	/* These should have been caught earlier. */
> +	WARN_ON(stride < 512);
> +	WARN_ON((stride & (64 - 1)) != 0);
> +
> +	/* Below are the additional FBC restrictions. */
> +
> +	if (IS_GEN2(dev_priv) || IS_GEN3(dev_priv))
> +		return stride == 4096 || stride == 8192;
> +
> +	if (IS_GEN4(dev_priv) && !IS_G4X(dev_priv) && stride < 2048)
> +		return false;
> +
> +	if (stride > 16384)
> +		return false;

Looks to match what I caught from my spec trawling trip last time.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> +
> +	return true;
> +}
> +
>  /**
>   * __intel_fbc_update - enable/disable FBC as needed, unlocked
>   * @dev_priv: i915 device instance
> @@ -781,6 +804,11 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
>  		goto out_disable;
>  	}
>  
> +	if (!stride_is_valid(dev_priv, fb->pitches[0])) {
> +		set_no_fbc_reason(dev_priv, FBC_BAD_STRIDE);
> +		goto out_disable;
> +	}
> +
>  	/* If the kernel debugger is active, always disable compression */
>  	if (in_dbg_master()) {
>  		set_no_fbc_reason(dev_priv, FBC_IN_DBG_MASTER);
> -- 
> 2.5.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3bf8a9b..8cf2969 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -948,6 +948,7 @@  struct i915_fbc {
 		FBC_CHIP_DEFAULT, /* disabled by default on this chip */
 		FBC_ROTATION, /* rotation is not supported */
 		FBC_IN_DBG_MASTER, /* kernel debugger is active */
+		FBC_BAD_STRIDE, /* stride is not supported */
 	} no_fbc_reason;
 
 	bool (*fbc_enabled)(struct drm_i915_private *dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 9e42079..db38091 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -480,6 +480,8 @@  const char *intel_no_fbc_reason_str(enum no_fbc_reason reason)
 		return "rotation unsupported";
 	case FBC_IN_DBG_MASTER:
 		return "Kernel debugger is active";
+	case FBC_BAD_STRIDE:
+		return "framebuffer stride not supported";
 	default:
 		MISSING_CASE(reason);
 		return "unknown reason";
@@ -671,6 +673,27 @@  static int intel_fbc_setup_cfb(struct drm_i915_private *dev_priv, int size,
 	return intel_fbc_alloc_cfb(dev_priv, size, fb_cpp);
 }
 
+static bool stride_is_valid(struct drm_i915_private *dev_priv,
+			    unsigned int stride)
+{
+	/* These should have been caught earlier. */
+	WARN_ON(stride < 512);
+	WARN_ON((stride & (64 - 1)) != 0);
+
+	/* Below are the additional FBC restrictions. */
+
+	if (IS_GEN2(dev_priv) || IS_GEN3(dev_priv))
+		return stride == 4096 || stride == 8192;
+
+	if (IS_GEN4(dev_priv) && !IS_G4X(dev_priv) && stride < 2048)
+		return false;
+
+	if (stride > 16384)
+		return false;
+
+	return true;
+}
+
 /**
  * __intel_fbc_update - enable/disable FBC as needed, unlocked
  * @dev_priv: i915 device instance
@@ -781,6 +804,11 @@  static void __intel_fbc_update(struct drm_i915_private *dev_priv)
 		goto out_disable;
 	}
 
+	if (!stride_is_valid(dev_priv, fb->pitches[0])) {
+		set_no_fbc_reason(dev_priv, FBC_BAD_STRIDE);
+		goto out_disable;
+	}
+
 	/* If the kernel debugger is active, always disable compression */
 	if (in_dbg_master()) {
 		set_no_fbc_reason(dev_priv, FBC_IN_DBG_MASTER);