Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758041AbeAICDw (ORCPT + 1 other); Mon, 8 Jan 2018 21:03:52 -0500 Received: from mail-pf0-f194.google.com ([209.85.192.194]:39398 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757942AbeAICDn (ORCPT ); Mon, 8 Jan 2018 21:03:43 -0500 X-Google-Smtp-Source: ACJfBouoZMBT4SkbRuloHk8mfSZH+xxRgUBRrOsDhmz245ckYnW/yA5sVcJuoM55zmx+AGoCT8Bjiw== From: Jonathan Liu To: Maxime Ripard , David Airlie , Chen-Yu Tsai Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@googlegroups.com, Jonathan Liu Subject: [PATCH v3 3/3] drm/sun4i: hdmi: Add missing rate halving check in sun4i_tmds_determine_rate Date: Tue, 9 Jan 2018 13:03:23 +1100 Message-Id: <20180109020323.11852-4-net147@gmail.com> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180109020323.11852-1-net147@gmail.com> References: <20180109020323.11852-1-net147@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: It was only checking the divider when determing the closest match if it could not match the requested rate exactly. For a projector connected to an Olimex A20-OLinuXino-LIME using HDMI with a native resolution of 1280x800 and pixel clock of 83.5 MHz, this resulted in 1280x800 mode not being available and the following in dmesg when the kernel is booted with drm.debug=0x3e: [drm:drm_mode_debug_printmodeline] Modeline 37:"1280x800" 60 83500 1280 1352 1480 1680 800 810 816 831 0x48 0x5 [drm:drm_mode_prune_invalid] Not using 1280x800 mode: NOCLOCK Fixes: 9c5681011a0c ("drm/sun4i: Add HDMI support") Signed-off-by: Jonathan Liu --- drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c index 88eeeaf34638..3ecffa52c814 100644 --- a/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c @@ -102,9 +102,12 @@ static int sun4i_tmds_determine_rate(struct clk_hw *hw, goto out; } - if (!best_parent || abs(rate - rounded / i) < - abs(rate - best_parent / best_div)) { + if (!best_parent || + abs(rate - rounded / i / j) < + abs(rate - best_parent / best_half / + best_div)) { best_parent = rounded; + best_half = i; best_div = j; } } -- 2.15.1