Re: [PATCH 1/7] drm/i915: create macros for the "unclaimed register" checks

[Ben Widawsky <ben@bwidawsk.net>]

On Fri, Jan 25, 2013 at 05:02:01PM -0800, Ben Widawsky wrote:
> On Fri, 25 Jan 2013 18:57:36 -0200
> Paulo Zanoni <przanoni@gmail.com> wrote:
> 
> > From: Paulo Zanoni <paulo.r.zanoni@intel.com>
> > 
> > This avoids polluting i915_write##x and also allows us to reuse code
> > on i915_read##x.
> > 
> > Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>

> > ---
> >  drivers/gpu/drm/i915/i915_drv.c |   24 ++++++++++++++++--------
> >  1 file changed, 16 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> > index 9cc8f87..ae0a55a 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.c
> > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > @@ -1224,6 +1224,20 @@ ilk_dummy_write(struct drm_i915_private *dev_priv)
> >  	I915_WRITE_NOTRACE(MI_MODE, 0);
> >  }
> >  
> > +#define UNCLAIMED_REG_CLEAR(dev_priv, reg) \
> > +	if (IS_HASWELL(dev_priv->dev) && \
> > +	    (I915_READ_NOTRACE(GEN7_ERR_INT) & ERR_INT_MMIO_UNCLAIMED)) { \
> > +		DRM_ERROR("Unknown unclaimed register before writing to %x\n", reg); \
> > +		I915_WRITE_NOTRACE(GEN7_ERR_INT, ERR_INT_MMIO_UNCLAIMED); \
> > +	}
> > +
> 
> You don't really need the if here, do you? I think the way it worked
> originally was fine.
I misread this the first time around. Please ignore this comment.
Apologies.
> 
> > +#define UNCLAIMED_REG_CHECK(dev_priv, reg) \
> > +	if (IS_HASWELL(dev_priv->dev) && \
> > +	    (I915_READ_NOTRACE(GEN7_ERR_INT) & ERR_INT_MMIO_UNCLAIMED)) { \
> > +		DRM_ERROR("Unclaimed write to %x\n", reg); \
> > +		writel(ERR_INT_MMIO_UNCLAIMED, dev_priv->regs + GEN7_ERR_INT);	\
> > +	}
> > +
> >  #define __i915_read(x, y) \
> >  u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg) { \
> >  	u##x val = 0; \
> 
> I suppose you could add some 'unlikely' predictions in another patch if
> you wanted. I really don't know what the consensus is on using those
> these day.
> 
> > @@ -1262,10 +1276,7 @@ void i915_write##x(struct drm_i915_private *dev_priv, u32 reg, u##x val) { \
> >  	} \
> >  	if (IS_GEN5(dev_priv->dev)) \
> >  		ilk_dummy_write(dev_priv); \
> > -	if (IS_HASWELL(dev_priv->dev) && (I915_READ_NOTRACE(GEN7_ERR_INT) & ERR_INT_MMIO_UNCLAIMED)) { \
> > -		DRM_ERROR("Unknown unclaimed register before writing to %x\n", reg); \
> > -		I915_WRITE_NOTRACE(GEN7_ERR_INT, ERR_INT_MMIO_UNCLAIMED); \
> > -	} \
> > +	UNCLAIMED_REG_CLEAR(dev_priv, reg); \
> >  	if (IS_VALLEYVIEW(dev_priv->dev) && IS_DISPLAYREG(reg)) { \
> >  		write##y(val, dev_priv->regs + reg + 0x180000);		\
> >  	} else {			\
> 
> Here's what I meant above, you replace 2 lines of code with 4 from the
> macro. (Including an extra MMIO read).
> 

I misread this the first time around. Please ignore this comment.
Apologies.

> > @@ -1274,10 +1285,7 @@ void i915_write##x(struct drm_i915_private *dev_priv, u32 reg, u##x val) { \
> >  	if (unlikely(__fifo_ret)) { \
> >  		gen6_gt_check_fifodbg(dev_priv); \
> >  	} \
> > -	if (IS_HASWELL(dev_priv->dev) && (I915_READ_NOTRACE(GEN7_ERR_INT) & ERR_INT_MMIO_UNCLAIMED)) { \
> > -		DRM_ERROR("Unclaimed write to %x\n", reg); \
> > -		writel(ERR_INT_MMIO_UNCLAIMED, dev_priv->regs + GEN7_ERR_INT);	\
> > -	} \
> > +	UNCLAIMED_REG_CHECK(dev_priv, reg); \
> >  }
> >  __i915_write(8, b)
> >  __i915_write(16, w)
> 
> 
> 
> -- 
> Ben Widawsky, Intel Open Source Technology Center
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ben Widawsky, Intel Open Source Technology Center