diff mbox

[4/6] drm/i915: add FBC_IN_DBG_MASTER no_fbc_reason

Message ID 1436293568-1674-5-git-send-email-przanoni@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Paulo Zanoni July 7, 2015, 6:26 p.m. UTC
From: Paulo Zanoni <paulo.r.zanoni@intel.com>

The poor in_dbg_master() check was the only one without a reason
string. Give it a reason string so it won't feel excluded.

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 | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

Comments

Daniel Vetter July 8, 2015, 9:38 a.m. UTC | #1
On Tue, Jul 07, 2015 at 03:26:06PM -0300, Paulo Zanoni wrote:
> From: Paulo Zanoni <paulo.r.zanoni@intel.com>
> 
> The poor in_dbg_master() check was the only one without a reason
> string. Give it a reason string so it won't feel excluded.
> 
> 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 | 6 +++++-
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 4ef1764..52d07fb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -935,6 +935,7 @@ struct i915_fbc {
>  		FBC_MODULE_PARAM,
>  		FBC_CHIP_DEFAULT, /* disabled by default on this chip */
>  		FBC_ROTATION, /* rotation is not supported */
> +		FBC_IN_DBG_MASTER, /* kernel debugger is active */

Oh dear this is dead code. kdbg uses the fbcon, which always uses
untiled, which means fbc will never be enabled. Also we have 0 users and 0
test coverage for kdbg on top of i915 (Jesse implemented it for fun years
back). Imo just remove all this code.
-Daniel

>  	} 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 9ef5b6c..8d39893 100644
> --- a/drivers/gpu/drm/i915/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/intel_fbc.c
> @@ -471,6 +471,8 @@ const char *intel_no_fbc_reason_str(enum no_fbc_reason reason)
>  		return "disabled per chip default";
>  	case FBC_ROTATION:
>  		return "rotation unsupported";
> +	case FBC_IN_DBG_MASTER:
> +		return "Kernel debugger is active";
>  	default:
>  		MISSING_CASE(reason);
>  		return "unknown reason";
> @@ -755,8 +757,10 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
>  	}
>  
>  	/* If the kernel debugger is active, always disable compression */
> -	if (in_dbg_master())
> +	if (in_dbg_master()) {
> +		set_no_fbc_reason(dev_priv, FBC_IN_DBG_MASTER);
>  		goto out_disable;
> +	}
>  
>  	if (intel_fbc_setup_cfb(dev_priv, obj->base.size,
>  				drm_format_plane_cpp(fb->pixel_format, 0))) {
> -- 
> 2.1.4
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Chris Wilson July 8, 2015, 9:53 a.m. UTC | #2
On Wed, Jul 08, 2015 at 11:38:02AM +0200, Daniel Vetter wrote:
> On Tue, Jul 07, 2015 at 03:26:06PM -0300, Paulo Zanoni wrote:
> > From: Paulo Zanoni <paulo.r.zanoni@intel.com>
> > 
> > The poor in_dbg_master() check was the only one without a reason
> > string. Give it a reason string so it won't feel excluded.
> > 
> > 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 | 6 +++++-
> >  2 files changed, 6 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index 4ef1764..52d07fb 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -935,6 +935,7 @@ struct i915_fbc {
> >  		FBC_MODULE_PARAM,
> >  		FBC_CHIP_DEFAULT, /* disabled by default on this chip */
> >  		FBC_ROTATION, /* rotation is not supported */
> > +		FBC_IN_DBG_MASTER, /* kernel debugger is active */
> 
> Oh dear this is dead code. kdbg uses the fbcon, which always uses
> untiled, which means fbc will never be enabled. Also we have 0 users and 0
> test coverage for kdbg on top of i915 (Jesse implemented it for fun years
> back). Imo just remove all this code.

A good kdbg integration would allow us to do allsorts of kprobes
debugging and igt fun. Ok, we could probably use kprobes...

* hatches evil plan to learn kprobes
-Chris
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 4ef1764..52d07fb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -935,6 +935,7 @@  struct i915_fbc {
 		FBC_MODULE_PARAM,
 		FBC_CHIP_DEFAULT, /* disabled by default on this chip */
 		FBC_ROTATION, /* rotation is not supported */
+		FBC_IN_DBG_MASTER, /* kernel debugger is active */
 	} 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 9ef5b6c..8d39893 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -471,6 +471,8 @@  const char *intel_no_fbc_reason_str(enum no_fbc_reason reason)
 		return "disabled per chip default";
 	case FBC_ROTATION:
 		return "rotation unsupported";
+	case FBC_IN_DBG_MASTER:
+		return "Kernel debugger is active";
 	default:
 		MISSING_CASE(reason);
 		return "unknown reason";
@@ -755,8 +757,10 @@  static void __intel_fbc_update(struct drm_i915_private *dev_priv)
 	}
 
 	/* If the kernel debugger is active, always disable compression */
-	if (in_dbg_master())
+	if (in_dbg_master()) {
+		set_no_fbc_reason(dev_priv, FBC_IN_DBG_MASTER);
 		goto out_disable;
+	}
 
 	if (intel_fbc_setup_cfb(dev_priv, obj->base.size,
 				drm_format_plane_cpp(fb->pixel_format, 0))) {