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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DBA16C43334 for ; Fri, 15 Jul 2022 09:37:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232274AbiGOJht (ORCPT ); Fri, 15 Jul 2022 05:37:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53742 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230138AbiGOJhs (ORCPT ); Fri, 15 Jul 2022 05:37:48 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 313AC7E817; Fri, 15 Jul 2022 02:37:47 -0700 (PDT) X-UUID: f3ab035118674bbeb578d2d49e5fa4d9-20220715 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.8,REQID:11a9fd0f-07cd-4713-a49d-0eb610ebc6bd,OB:0,LO B:10,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:51,FILE:0,RULE:Release_Ham,AC TION:release,TS:51 X-CID-INFO: VERSION:1.1.8,REQID:11a9fd0f-07cd-4713-a49d-0eb610ebc6bd,OB:0,LOB: 10,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:51,FILE:0,RULE:Release_Ham,ACTI ON:release,TS:51 X-CID-META: VersionHash:0f94e32,CLOUDID:fba91433-b9e4-42b8-b28a-6364427c76bb,C OID:0c5cc15b0205,Recheck:0,SF:28|17|19|48,TC:nil,Content:0,EDM:-3,IP:nil,U RL:0,File:nil,QS:nil,BEC:nil,COL:0 X-UUID: f3ab035118674bbeb578d2d49e5fa4d9-20220715 Received: from mtkmbs10n1.mediatek.inc [(172.21.101.34)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 2019365385; Fri, 15 Jul 2022 17:37:43 +0800 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) by mtkmbs11n2.mediatek.inc (172.21.101.187) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.792.3; Fri, 15 Jul 2022 17:37:42 +0800 Received: from mtksdccf07 (172.21.84.99) by mtkmbs11n2.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.792.3 via Frontend Transport; Fri, 15 Jul 2022 17:37:42 +0800 Message-ID: Subject: Re: [PATCH v14 05/10] drm/mediatek: Add MT8195 Embedded DisplayPort driver From: CK Hu To: Bo-Chen Chen , , , , , , , , , , CC: , , , , , , , , , , , , Date: Fri, 15 Jul 2022 17:37:42 +0800 In-Reply-To: <20220712111223.13080-6-rex-bc.chen@mediatek.com> References: <20220712111223.13080-1-rex-bc.chen@mediatek.com> <20220712111223.13080-6-rex-bc.chen@mediatek.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Hi, Bo-Chen: On Tue, 2022-07-12 at 19:12 +0800, Bo-Chen Chen wrote: > From: Markus Schneider-Pargmann > > This patch adds a embedded displayport driver for the MediaTek mt8195 > SoC. > > It supports the MT8195, the embedded DisplayPort units. It offers > DisplayPort 1.4 with up to 4 lanes. > > The driver creates a child device for the phy. The child device will > never exist without the parent being active. As they are sharing a > register range, the parent passes a regmap pointer to the child so > that > both can work with the same register range. The phy driver sets > device > data that is read by the parent to get the phy device that can be > used > to control the phy properties. > > This driver is based on an initial version by > Jitao shi > > Signed-off-by: Markus Schneider-Pargmann > Signed-off-by: Guillaume Ranquet > Signed-off-by: Bo-Chen Chen > --- [snip] > + > +static enum drm_mode_status > +mtk_dp_bridge_mode_valid(struct drm_bridge *bridge, > + const struct drm_display_info *info, > + const struct drm_display_mode *mode) > +{ > + struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge); > + u32 rx_linkrate = (u32)mtk_dp->train_info.link_rate * 27000; > + u32 bpp = info->color_formats & DRM_COLOR_FORMAT_YCBCR422 ? 16 > : 24; > + > + if (rx_linkrate * mtk_dp->train_info.lane_count < mode->clock * > bpp / 8) > + return MODE_CLOCK_HIGH; > + > + if (mode->clock > 600000) > + return MODE_CLOCK_HIGH; > + > + if ((mode->clock * 1000) / (mode->htotal * mode->vtotal) > > + MTK_VDOSYS1_MAX_FRAMERATE) Why limit frame rate to 60fps? If the resolution is small enough, why not support higher fps? Regards, CK > + return MODE_CLOCK_HIGH; > + > + return MODE_OK; > +} > +