From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45754C49ED7 for ; Fri, 20 Sep 2019 14:25:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27C7421835 for ; Fri, 20 Sep 2019 14:25:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388316AbfITOZL (ORCPT ); Fri, 20 Sep 2019 10:25:11 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36520 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388286AbfITOZL (ORCPT ); Fri, 20 Sep 2019 10:25:11 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iBJqN-00051H-M8; Fri, 20 Sep 2019 15:25:07 +0100 Received: from ben by deadeye with local (Exim 4.92.1) (envelope-from ) id 1iBJqG-0007vy-7D; Fri, 20 Sep 2019 15:25:00 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Paul Dufresne" , "=?UTF-8?q?Christian=20K=C3=B6nig?=" , "Alex Deucher" Date: Fri, 20 Sep 2019 15:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 092/132] drm/radeon: prefer lower reference dividers In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.16.74-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Christian König commit 2e26ccb119bde03584be53406bbd22e711b0d6e6 upstream. Instead of the closest reference divider prefer the lowest, this fixes flickering issues on HP Compaq nx9420. Bugs: https://bugs.freedesktop.org/show_bug.cgi?id=108514 Suggested-by: Paul Dufresne Signed-off-by: Christian König Acked-by: Alex Deucher Signed-off-by: Alex Deucher [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- drivers/gpu/drm/radeon/radeon_display.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -942,12 +942,12 @@ static void avivo_get_fb_ref_div(unsigne ref_div_max = max(min(100 / post_div, ref_div_max), 1u); /* get matching reference and feedback divider */ - *ref_div = min(max(DIV_ROUND_CLOSEST(den, post_div), 1u), ref_div_max); + *ref_div = min(max(den/post_div, 1u), ref_div_max); *fb_div = DIV_ROUND_CLOSEST(nom * *ref_div * post_div, den); /* limit fb divider to its maximum */ if (*fb_div > fb_div_max) { - *ref_div = DIV_ROUND_CLOSEST(*ref_div * fb_div_max, *fb_div); + *ref_div = (*ref_div * fb_div_max)/(*fb_div); *fb_div = fb_div_max; } }