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 DAA38C43334 for ; Wed, 8 Jun 2022 04:43:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232830AbiFHEnH (ORCPT ); Wed, 8 Jun 2022 00:43:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231529AbiFHEmO (ORCPT ); Wed, 8 Jun 2022 00:42:14 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0C95414780; Tue, 7 Jun 2022 19:34:18 -0700 (PDT) X-UUID: d0c4507de4df4791bd72f8ff104955c9-20220608 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.5,REQID:c312a6f2-4170-4211-b8d3-77a887bc844b,OB:0,LO B:0,IP:0,URL:5,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,RULE:Release_Ham,ACTI ON:release,TS:5 X-CID-META: VersionHash:2a19b09,CLOUDID:4db28e7e-c8dc-403a-96e8-6237210dceee,C OID:IGNORED,Recheck:0,SF:nil,TC:nil,Content:0,EDM:-3,IP:nil,URL:1,File:nil ,QS:0,BEC:nil X-UUID: d0c4507de4df4791bd72f8ff104955c9-20220608 Received: from mtkmbs11n1.mediatek.inc [(172.21.101.185)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 1403095489; Wed, 08 Jun 2022 10:23:10 +0800 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) by mtkmbs10n1.mediatek.inc (172.21.101.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.792.15; Wed, 8 Jun 2022 10:23:08 +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; Wed, 8 Jun 2022 10:23:08 +0800 Message-ID: <358331497a5ff431d46bfea9c5c9dcadfaaa9a63.camel@mediatek.com> Subject: Re: [PATCH v10 18/21] drm/mediatek: Add mt8195 Embedded DisplayPort driver From: CK Hu To: Rex-BC Chen , Guillaume Ranquet , Chun-Kuang Hu , "Philipp Zabel" , David Airlie , "Daniel Vetter" , Rob Herring , "Krzysztof Kozlowski" , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Matthias Brugger , Chunfeng Yun =?UTF-8?Q?=28=E4=BA=91=E6=98=A5=E5=B3=B0=29?= , Kishon Vijay Abraham I , Vinod Koul , "Helge Deller" , Jitao Shi =?UTF-8?Q?=28=E7=9F=B3=E8=AE=B0=E6=B6=9B=29?= CC: Markus Schneider-Pargmann , "dri-devel@lists.freedesktop.org" , "linux-mediatek@lists.infradead.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-phy@lists.infradead.org" , "linux-fbdev@vger.kernel.org" Date: Wed, 8 Jun 2022 10:23:08 +0800 In-Reply-To: <8af7938ae9244e4b7caf62e0c6ce0bcdddc13889.camel@mediatek.com> References: <20220523104758.29531-1-granquet@baylibre.com> <20220523104758.29531-19-granquet@baylibre.com> <0bd8b0c66b9e2a1b63280e7eab63048bee7fe786.camel@mediatek.com> <8af7938ae9244e4b7caf62e0c6ce0bcdddc13889.camel@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-kernel@vger.kernel.org Hi, Rex: On Tue, 2022-06-07 at 20:24 +0800, Rex-BC Chen wrote: > On Tue, 2022-06-07 at 14:21 +0800, CK Hu wrote: > > Hi, Rex: > > > > On Mon, 2022-05-23 at 12:47 +0200, Guillaume Ranquet wrote: > > > From: Markus Schneider-Pargmann > > > > > > This patch adds a 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 > > > Jason-JH.Lin . > > > > > > Signed-off-by: Markus Schneider-Pargmann > > > Signed-off-by: Guillaume Ranquet > > > --- > > > > [snip] > > > > > + > > > +static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev) > > > +{ > > > + struct mtk_dp *mtk_dp = dev; > > > + int event; > > > + u8 buf[DP_RECEIVER_CAP_SIZE] = {}; > > > + > > > + event = mtk_dp_plug_state(mtk_dp) ? connector_status_connected > > > : > > > + connector_status_disc > > > onnected; > > > + > > > + if (event < 0) > > > > event is always > 0, isn't it? > > > > Hello CK, > > ok, I will move this to dp patch. > > > > + return IRQ_HANDLED; > > > + > > > + if (mtk_dp->drm_dev) { > > > + dev_info(mtk_dp->dev, "drm_helper_hpd_irq_event\n"); > > > + drm_helper_hpd_irq_event(mtk_dp->bridge.dev); > > > > I think this ISR would come once. If bridge has not attached, the > > drm > > core would lost this event. Maybe you should enable eDP hardware > > after > > bridge attached or send this event when attached. > > > > for edp patch, I will move it to (mtk_dp_bridge_attach). > for dp patch, I will add it back. I find out that mtk_dp_poweron() is in top of mtk_dp_bridge_attach(). If move mtk_dp_poweron() to bottom of mtk_dp_bridge_attach(), mtk_dp- >drm_dev would not be NULL here. So we could drop this checking. > > > > + } > > > + > > > + if (mtk_dp->train_info.cable_state_change) { > > > > Executing this thread imply cable_state_change = true, so drop > > cable_state_change. > > > > In mtk_dp_hpd_isr_handler(), there is another irq > "MTK_DP_HPD_INTERRUPT" which means the sink devices give a interrupt > to > source device. it's not about connected status, so I think we still > need this. In bottom of mtk_dp_hpd_isr_handler(), the code is: + train_info->cable_state_change = true; + + return IRQ_WAKE_THREAD; This thread is called only when return IRQ_WAKE_THREAD, and before return IRQ_WAKE_THREAD, train_info->cable_state_change is always set to true. So in this thread, train_info->cable_state_change must be true. Regards, CK > > > > + mtk_dp->train_info.cable_state_change = false; > > > + > > > + mtk_dp->train_state = MTK_DP_TRAIN_STATE_STARTUP; > > > + > > > + if (!mtk_dp->train_info.cable_plugged_in || > > > + !mtk_dp_plug_state(mtk_dp)) { > > > > I do not like two variable to present one thing. If > > > > mtk_dp->train_info.cable_plugged_in = false > > and > > mtk_dp_plug_state(mtk_dp) = ture > > > > What does this mean? I think this mean 'now' is connected because > > cable_plugged_in is old information and mtk_dp_plug_state() is > > current > > information. > > > > But I would like to keep cable_plugged_in and drop > > mtk_dp_plug_state() > > because cable_plugged_in would be changed in isr and it would be > > the > > same as mtk_dp_plug_state(). > > > > Regards, > > CK > > > > ok, I will drop this. > > BRs, > Rex > > > > + mtk_dp_video_mute(mtk_dp, true); > > > + > > > + mtk_dp_initialize_priv_data(mtk_dp); > > > + mtk_dp_set_idle_pattern(mtk_dp, true); > > > + if (mtk_dp->has_fec) > > > + mtk_dp_fec_enable(mtk_dp, false); > > > + > > > + mtk_dp_update_bits(mtk_dp, > > > MTK_DP_TOP_PWR_STATE, > > > + DP_PWR_STATE_BANDGAP_TPLL, > > > + DP_PWR_STATE_MASK); > > > + } else { > > > + mtk_dp_update_bits(mtk_dp, > > > MTK_DP_TOP_PWR_STATE, > > > + DP_PWR_STATE_BANDGAP_TPLL_LA > > > NE, > > > + DP_PWR_STATE_MASK); > > > + drm_dp_read_dpcd_caps(&mtk_dp->aux, buf); > > > + mtk_dp->train_info.link_rate = > > > + min_t(int, mtk_dp->max_linkrate, > > > + buf[mtk_dp->max_linkrate]); > > > + mtk_dp->train_info.lane_count = > > > + min_t(int, mtk_dp->max_lanes, > > > + drm_dp_max_lane_count(buf)); > > > + } > > > + } > > > + > > > + if (mtk_dp->train_info.irq_status & MTK_DP_HPD_INTERRUPT) { > > > + dev_dbg(mtk_dp->dev, "MTK_DP_HPD_INTERRUPT\n"); > > > + mtk_dp->train_info.irq_status &= ~MTK_DP_HPD_INTERRUPT; > > > + mtk_dp_hpd_sink_event(mtk_dp); > > > + } > > > + > > > + return IRQ_HANDLED; > > > +} > > > + > > > > > >