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* [PATCH] drm/i915/bdw: Don't use forcewake needlessly
@ 2013-12-10 13:24 ville.syrjala
  2013-12-10 19:47 ` Ben Widawsky
  0 siblings, 1 reply; 4+ messages in thread
From: ville.syrjala @ 2013-12-10 13:24 UTC (permalink / raw)
  To: intel-gfx

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Not all registers need forcewake even if they're not shadowed.
Add the missing NEEDS_FORCE_WAKE() check to gen8_writeX() to
avoid needless forcewake usage when writing eg. display
registers.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
I didn't test this at all, so be warned.

 drivers/gpu/drm/i915/intel_uncore.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index e63658e..78fe8d6 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -616,7 +616,8 @@ static bool is_gen8_shadowed(struct drm_i915_private *dev_priv, u32 reg)
 #define __gen8_write(x) \
 static void \
 gen8_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
-	bool __needs_put = !is_gen8_shadowed(dev_priv, reg); \
+	bool __needs_put = NEEDS_FORCE_WAKE(dev_priv, reg) && \
+		!is_gen8_shadowed(dev_priv, reg); \
 	REG_WRITE_HEADER; \
 	if (__needs_put) { \
 		dev_priv->uncore.funcs.force_wake_get(dev_priv, \
-- 
1.8.3.2

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^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] drm/i915/bdw: Don't use forcewake needlessly
  2013-12-10 13:24 [PATCH] drm/i915/bdw: Don't use forcewake needlessly ville.syrjala
@ 2013-12-10 19:47 ` Ben Widawsky
  2013-12-10 22:30   ` Daniel Vetter
  2013-12-13 11:26   ` [PATCH v2] " ville.syrjala
  0 siblings, 2 replies; 4+ messages in thread
From: Ben Widawsky @ 2013-12-10 19:47 UTC (permalink / raw)
  To: ville.syrjala; +Cc: intel-gfx

On Tue, Dec 10, 2013 at 03:24:52PM +0200, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Not all registers need forcewake even if they're not shadowed.
> Add the missing NEEDS_FORCE_WAKE() check to gen8_writeX() to
> avoid needless forcewake usage when writing eg. display
> registers.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> I didn't test this at all, so be warned.
> 
>  drivers/gpu/drm/i915/intel_uncore.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index e63658e..78fe8d6 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -616,7 +616,8 @@ static bool is_gen8_shadowed(struct drm_i915_private *dev_priv, u32 reg)
>  #define __gen8_write(x) \
>  static void \
>  gen8_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
> -	bool __needs_put = !is_gen8_shadowed(dev_priv, reg); \
> +	bool __needs_put = NEEDS_FORCE_WAKE(dev_priv, reg) && \
> +		!is_gen8_shadowed(dev_priv, reg); \
>  	REG_WRITE_HEADER; \
>  	if (__needs_put) { \
>  		dev_priv->uncore.funcs.force_wake_get(dev_priv, \

I would prefer if this was simply checking the display offset, as
opposed to NEEDS_FORCE_WAKE - since if someone adds to the macro we run
the risk of a potentially hard to track down bug.

In any case, the patch is functionally correct, and I'd prefer the
change, but up to you:
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>

> -- 
> 1.8.3.2
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ben Widawsky, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] drm/i915/bdw: Don't use forcewake needlessly
  2013-12-10 19:47 ` Ben Widawsky
@ 2013-12-10 22:30   ` Daniel Vetter
  2013-12-13 11:26   ` [PATCH v2] " ville.syrjala
  1 sibling, 0 replies; 4+ messages in thread
From: Daniel Vetter @ 2013-12-10 22:30 UTC (permalink / raw)
  To: Ben Widawsky; +Cc: intel-gfx

On Tue, Dec 10, 2013 at 11:47:17AM -0800, Ben Widawsky wrote:
> On Tue, Dec 10, 2013 at 03:24:52PM +0200, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Not all registers need forcewake even if they're not shadowed.
> > Add the missing NEEDS_FORCE_WAKE() check to gen8_writeX() to
> > avoid needless forcewake usage when writing eg. display
> > registers.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> > I didn't test this at all, so be warned.
> > 
> >  drivers/gpu/drm/i915/intel_uncore.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> > index e63658e..78fe8d6 100644
> > --- a/drivers/gpu/drm/i915/intel_uncore.c
> > +++ b/drivers/gpu/drm/i915/intel_uncore.c
> > @@ -616,7 +616,8 @@ static bool is_gen8_shadowed(struct drm_i915_private *dev_priv, u32 reg)
> >  #define __gen8_write(x) \
> >  static void \
> >  gen8_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
> > -	bool __needs_put = !is_gen8_shadowed(dev_priv, reg); \
> > +	bool __needs_put = NEEDS_FORCE_WAKE(dev_priv, reg) && \
> > +		!is_gen8_shadowed(dev_priv, reg); \
> >  	REG_WRITE_HEADER; \
> >  	if (__needs_put) { \
> >  		dev_priv->uncore.funcs.force_wake_get(dev_priv, \
> 
> I would prefer if this was simply checking the display offset, as
> opposed to NEEDS_FORCE_WAKE - since if someone adds to the macro we run
> the risk of a potentially hard to track down bug.

Yeah, I agree that an explicit check would be better since the forcewake
stuff works a bit different on gen8+
-Daniel

> 
> In any case, the patch is functionally correct, and I'd prefer the
> change, but up to you:
> Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> 
> > -- 
> > 1.8.3.2
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Ben Widawsky, Intel Open Source Technology Center
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v2] drm/i915/bdw: Don't use forcewake needlessly
  2013-12-10 19:47 ` Ben Widawsky
  2013-12-10 22:30   ` Daniel Vetter
@ 2013-12-13 11:26   ` ville.syrjala
  1 sibling, 0 replies; 4+ messages in thread
From: ville.syrjala @ 2013-12-13 11:26 UTC (permalink / raw)
  To: intel-gfx; +Cc: Ben Widawsky

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Not all registers need forcewake even if they're not shadowed.
Add the missing check to gen8_writeX() to avoid needless forcewake
usage when writing eg. display registers.

v2: Use straight up <0x40000 check instead of NEEDS_FORCE_WAKE()

Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 8102af9..3fa1409 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -629,7 +629,7 @@ static bool is_gen8_shadowed(struct drm_i915_private *dev_priv, u32 reg)
 #define __gen8_write(x) \
 static void \
 gen8_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
-	bool __needs_put = !is_gen8_shadowed(dev_priv, reg); \
+	bool __needs_put = reg < 0x40000 && !is_gen8_shadowed(dev_priv, reg); \
 	REG_WRITE_HEADER; \
 	if (__needs_put) { \
 		dev_priv->uncore.funcs.force_wake_get(dev_priv, \
-- 
1.8.3.2

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^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2013-12-13 11:26 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2013-12-10 13:24 [PATCH] drm/i915/bdw: Don't use forcewake needlessly ville.syrjala
2013-12-10 19:47 ` Ben Widawsky
2013-12-10 22:30   ` Daniel Vetter
2013-12-13 11:26   ` [PATCH v2] " ville.syrjala

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