From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= <ville.syrjala@linux.intel.com>
Subject: Re: [PATCH 4/9] drm/i915: fix haswell linetime
 watermarks calculation
Date: Mon, 20 May 2013 16:53:28 +0300
Message-ID: <20130520135328.GH14974@intel.com>
References: <1367612625-4823-1-git-send-email-przanoni@gmail.com>
	<1367612625-4823-5-git-send-email-przanoni@gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Return-path: <intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org>
Received: from mga03.intel.com (mga03.intel.com [143.182.124.21])
	by gabe.freedesktop.org (Postfix) with ESMTP id EFEF3E5E53
	for <intel-gfx@lists.freedesktop.org>;
	Mon, 20 May 2013 06:53:33 -0700 (PDT)
Content-Disposition: inline
In-Reply-To: <1367612625-4823-5-git-send-email-przanoni@gmail.com>
List-Unsubscribe: <http://lists.freedesktop.org/mailman/options/intel-gfx>,
	<mailto:intel-gfx-request@lists.freedesktop.org?subject=unsubscribe>
List-Archive: <http://lists.freedesktop.org/archives/intel-gfx>
List-Post: <mailto:intel-gfx@lists.freedesktop.org>
List-Help: <mailto:intel-gfx-request@lists.freedesktop.org?subject=help>
List-Subscribe: <http://lists.freedesktop.org/mailman/listinfo/intel-gfx>,
	<mailto:intel-gfx-request@lists.freedesktop.org?subject=subscribe>
Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org
Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org
To: Paulo Zanoni <przanoni@gmail.com>
Cc: intel-gfx@lists.freedesktop.org, Paulo Zanoni <paulo.r.zanoni@intel.com>
List-Id: intel-gfx@lists.freedesktop.org

On Fri, May 03, 2013 at 05:23:40PM -0300, Paulo Zanoni wrote:
> From: Paulo Zanoni <paulo.r.zanoni@intel.com>
> =

> Move the "*8"  calculation to the left side so we don't propagate
> rounding errors. Also use DIV_ROUND_CLOSEST because that's what the
> spec says we need to do.
> =

> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>

Reviewed-by: Ville Syrj=E4l=E4 <ville.syrjala@linux.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 4cc5f99..8468b40 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 |=3D PIPE_WM_LINETIME_TIME(
> -		((mode->htotal * 1000) / mode->clock) * 8);
> +		DIV_ROUND_CLOSEST(mode->htotal * 1000 * 8, mode->clock));
>  =

>  	/* 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
> =

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

-- =

Ville Syrj=E4l=E4
Intel OTC