[Intel-gfx] [PATCH 3/9] drm/i915: use the mode->htotal to calculate linetime watermarks

[Daniel Vetter]

On Fri, May 03, 2013 at 05:23:39PM -0300, Paulo Zanoni wrote:
> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
> 
> ... instead of mode->crtc_display. The spec says "pipe horizontal
> total number of pixels" and the "Haswell Watermark Calculator" tool
> uses the "Pipe H Total" instead of "Pipe H Src" as the value.
> 
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_pm.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index d056bc9..4cc5f99 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -2035,7 +2035,7 @@ haswell_update_linetime_wm(struct drm_device *dev, struct drm_crtc *crtc)
>  	 * row at the given clock rate, multiplied by 8.
>  	 * */
>  	temp |= PIPE_WM_LINETIME_TIME(
> -		((mode->crtc_hdisplay * 1000) / mode->clock) * 8);
> +		((mode->htotal * 1000) / mode->clock) * 8);

Big question: What's the right value for interlaced modes? On progressive
mode crtc_ mode values match the non-crtc_ prefixed ones, but not so much
for interlaced modes ... So if your tool expects something resembling what
we program into the pipe registers, we need to change this again.

Merged for now since the spec explicitly says "pixels", but I'd like
someone to double-check this.
-Daniel
>  
>  	/* IPS watermarks are only used by pipe A, and are ignored by
>  	 * pipes B and C.  They are calculated similarly to the common
> -- 
> 1.7.10.4
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch