From: Chris Wilson <chris@chris-wilson.co.uk>
To: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 2/2] drm/i915: Refactor panel fitting on the LVDS.
Date: Sat, 17 Jul 2010 13:48:22 +0100 [thread overview]
Message-ID: <89k83a$8v8ql7@azsmga001.ch.intel.com> (raw)
In-Reply-To: <1279370324-12761-2-git-send-email-chris@chris-wilson.co.uk>
On Sat, 17 Jul 2010 13:38:44 +0100, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> +static inline u32 panel_fitter_scaling(u32 source, u32 target)
> +{
> + /*
> + * Floating point operation is not supported. So the FACTOR
> + * is defined, which can avoid the floating point computation
> + * when calculating the panel ratio.
> + */
> +#define ACCURACY 12
> +#define FACTOR (1 << ACCURACY)
> + u32 ratio = source * FACTOR / target;
> + return (FACTOR * (ratio + FACTOR/2)) / FACTOR;
> +}
Rounding went wrong here. Should be
return (FACTOR * ratio + FACTOR/2) / FACTOR;
--
Chris Wilson, Intel Open Source Technology Centre
next prev parent reply other threads:[~2010-07-17 12:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-17 12:38 [PATCH 1/2] drm/i915: Remove the redundant check for a fixed_panel_mode Chris Wilson
2010-07-17 12:38 ` [PATCH 2/2] drm/i915: Refactor panel fitting on the LVDS Chris Wilson
2010-07-17 12:48 ` Chris Wilson [this message]
2010-07-18 1:15 ` Jesse Barnes
2010-07-18 11:07 ` Chris Wilson
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