From patchwork Tue Oct 29 18:06:10 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= X-Patchwork-Id: 3109931 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 9D8589F2B7 for ; Tue, 29 Oct 2013 18:07:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7EEF1200E7 for ; Tue, 29 Oct 2013 18:07:24 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 1BDAA20204 for ; Tue, 29 Oct 2013 18:07:23 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 44854EEC4D; Tue, 29 Oct 2013 11:07:05 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTP id 22FFFEEC4A; Tue, 29 Oct 2013 11:06:53 -0700 (PDT) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 29 Oct 2013 11:03:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,535,1378882800"; d="scan'208";a="426611660" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.98]) by orsmga002.jf.intel.com with SMTP; 29 Oct 2013 11:06:50 -0700 Received: by stinkbox (sSMTP sendmail emulation); Tue, 29 Oct 2013 20:06:49 +0200 From: ville.syrjala@linux.intel.com To: dri-devel@lists.freedesktop.org Subject: [PATCH 06/14] drm: Simplify the math in drm_calc_timestamping_constants() Date: Tue, 29 Oct 2013 20:06:10 +0200 Message-Id: <1383069978-12476-7-git-send-email-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1383069978-12476-1-git-send-email-ville.syrjala@linux.intel.com> References: <1383069978-12476-1-git-send-email-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Cc: intel-gfx@lists.freedesktop.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Ville Syrjälä drm_calc_timestamping_constants() makes the math more complex than necessary. - multipying the dotclock by 1000 is pointless, just makes all the numbers bigger - div64_u64() is also pointless, div_u64 is enough - pixeldur_ns doesn't need any 64bit math Signed-off-by: Ville Syrjälä --- drivers/gpu/drm/drm_irq.c | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 48bf91f..d6ef034 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -451,10 +451,7 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc, const struct drm_display_mode *mode) { s64 linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0; - u64 dotclock; - - /* Dot clock in Hz: */ - dotclock = (u64) mode->clock * 1000; + int dotclock = mode->clock; /* Fields of interlaced scanout modes are only halve a frame duration. * Double the dotclock to get halve the frame-/line-/pixelduration. @@ -464,17 +461,16 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc, /* Valid dotclock? */ if (dotclock > 0) { - int frame_size; - /* Convert scanline length in pixels and video dot clock to - * line duration, frame duration and pixel duration in - * nanoseconds: + int frame_size = mode->crtc_htotal * mode->crtc_vtotal; + + /* + * Convert scanline length in pixels and video + * dot clock to line duration, frame duration + * and pixel duration in nanoseconds: */ - pixeldur_ns = (s64) div64_u64(1000000000, dotclock); - linedur_ns = (s64) div64_u64(((u64) mode->crtc_htotal * - 1000000000), dotclock); - frame_size = mode->crtc_htotal * mode->crtc_vtotal; - framedur_ns = (s64) div64_u64((u64) frame_size * 1000000000, - dotclock); + pixeldur_ns = 1000000 / dotclock; + linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock); + framedur_ns = div_u64((u64) frame_size * 1000000, dotclock); } else DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n", crtc->base.id); @@ -487,7 +483,7 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc, crtc->base.id, mode->crtc_htotal, mode->crtc_vtotal, mode->crtc_vdisplay); DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n", - crtc->base.id, (int) dotclock/1000, (int) framedur_ns, + crtc->base.id, dotclock, (int) framedur_ns, (int) linedur_ns, (int) pixeldur_ns); } EXPORT_SYMBOL(drm_calc_timestamping_constants);