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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DFF18C43334 for ; Wed, 8 Jun 2022 10:33:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:CC:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ZKHaoLB1OD/25mqgVl6IPNdmhUn2znk0CFP05p6b7As=; b=b9hrpLL0E0HEzt bREWObflV3QKYNT2TU6l35ni8cKAiYHF5YmKB0RtsPfxZSwert56IKYCV1jI7jhRR/CeCT23aWxk3 O5e7/FGjG4R0fU0PGsYVQiseYYP2IZTmigC7SbnYs9EJjFr15PtVMSkR6POsnPPUmXhQ2whYtqV4o Ka2gRY4+x42poJAcZuGkf1YDPe75eCSc9s42fkgTHdu1sB7/h2AVfwffB1eRsTEjevOB+jHYy4S29 RE/ZnTb1zdO5mMaPBGrnxnld/Y3axwzauX0tnJdQXPxkTitSeTygjbri+HwYjrpeZS0mjmBxk/CDL ydGSl+OlynvhfMUbHCNA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nyt00-00CmbF-6R; Wed, 08 Jun 2022 10:33:16 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nyszZ-00CmRR-Tu; Wed, 08 Jun 2022 10:32:51 +0000 X-UUID: 29a09333834d412191c513514a993246-20220608 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.5,REQID:aba5328e-8a34-46c1-a5f8-214a1995933e,OB:0,LO B:0,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,RULE:Release_Ham,ACTI ON:release,TS:0 X-CID-META: VersionHash:2a19b09,CLOUDID:04f219e5-2ba2-4dc1-b6c5-11feb6c769e0,C OID:IGNORED,Recheck:0,SF:nil,TC:nil,Content:0,EDM:-3,IP:nil,URL:0,File:nil ,QS:0,BEC:nil X-UUID: 29a09333834d412191c513514a993246-20220608 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1596128052; Wed, 08 Jun 2022 03:32:42 -0700 Received: from mtkmbs10n1.mediatek.inc (172.21.101.34) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 8 Jun 2022 03:26:35 -0700 Received: from mtkmbs11n1.mediatek.inc (172.21.101.186) 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 18:26:34 +0800 Received: from mtksdccf07 (172.21.84.99) by mtkmbs11n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.792.3 via Frontend Transport; Wed, 8 Jun 2022 18:26:33 +0800 Message-ID: <75c00caca74b8366ca2c4594a8229b6de95c5f47.camel@mediatek.com> Subject: Re: [PATCH v10 18/21] drm/mediatek: Add mt8195 Embedded DisplayPort driver From: Rex-BC Chen To: CK Hu , 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 18:26:33 +0800 In-Reply-To: References: <20220523104758.29531-1-granquet@baylibre.com> <20220523104758.29531-19-granquet@baylibre.com> X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220608_033250_018885_54B50F66 X-CRM114-Status: GOOD ( 29.81 ) X-BeenThere: linux-phy@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux Phy Mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-phy" Errors-To: linux-phy-bounces+linux-phy=archiver.kernel.org@lists.infradead.org On Tue, 2022-06-07 at 15:47 +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 int mtk_dp_hpd_sink_event(struct mtk_dp *mtk_dp) > > +{ > > + ssize_t ret; > > + u8 sink_count; > > + bool locked; > > + u8 link_status[DP_LINK_STATUS_SIZE] = {}; > > + u32 sink_count_reg = DP_SINK_COUNT_ESI; > > + u32 link_status_reg = DP_LANE0_1_STATUS; > > + > > + ret = drm_dp_dpcd_readb(&mtk_dp->aux, sink_count_reg, > > &sink_count); > > + if (ret < 0) { > > + drm_err(mtk_dp->drm_dev, "Read sink count failed: > > %ld\n", ret); > > + return ret; > > + } > > + > > + ret = drm_dp_dpcd_read(&mtk_dp->aux, link_status_reg, > > link_status, > > + sizeof(link_status)); > > + if (!ret) { > > + drm_err(mtk_dp->drm_dev, "Read link status failed: > > %ld\n", > > + ret); > > + return ret; > > + } > > + > > + locked = drm_dp_channel_eq_ok(link_status, > > + mtk_dp->train_info.lane_count); > > + if (!locked && mtk_dp->train_state > > > MTK_DP_TRAIN_STATE_TRAINING_PRE) > > Before enter this function, mtk_dp->train_state is set to > MTK_DP_TRAIN_STATE_STARTUP, so this never happen, drop this. > The interrupt from sink device could come any time. Why it's impossible? > > + mtk_dp->train_state = MTK_DP_TRAIN_STATE_TRAINING_PRE; > > + > > + if (link_status[1] & DP_REMOTE_CONTROL_COMMAND_PENDING) > > + drm_dp_dpcd_writeb(&mtk_dp->aux, > > DP_DEVICE_SERVICE_IRQ_VECTOR, > > + DP_REMOTE_CONTROL_COMMAND_PENDING); > > + > > + if (DP_GET_SINK_COUNT(sink_count) && > > + (link_status[2] & DP_DOWNSTREAM_PORT_STATUS_CHANGED)) { > > + mtk_dp->train_info.check_cap_count = 0; > > + mtk_dp->train_state = MTK_DP_TRAIN_STATE_CHECKEDID; > > Why change state from MTK_DP_TRAIN_STATE_STARTUP to > MTK_DP_TRAIN_STATE_CHECKEDID? In mtk_dp_train_handler(), > mtk_dp_parse_capabilities() is true then change to > MTK_DP_TRAIN_STATE_CHECKEDID. Give a reason why these two are > different. > > Regards, > CK > I will drop this and drop state of MTK_DP_TRAIN_STATE_CHECKEDID. MTK_DP_TRAIN_STATE_CHECKEDID is only used for audio. We can check enable status in another place. BRs, Bo-Chen > > + msleep(20); > > + } > > + > > + return 0; > > +} > > + > > -- linux-phy mailing list linux-phy@lists.infradead.org https://lists.infradead.org/mailman/listinfo/linux-phy