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 C51B5C433EF for ; Tue, 7 Jun 2022 06:46:38 +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=H+QC2Leo8XeT8i1I3rNxJd9K/bLCh6MHlawRpZ+/0+4=; b=qBbaONMpqQRokO l8dO6ITa6/fcKjLX3vaLvXA+K/y9rYg6dfl0pJTQ2ZSteKnxHjgXiUYP81tQXhCd2CcgaRs4jmDpt /HGTbGbDinHdFx2LWTsdxcubfIF+oJO4X64JUPxJiHQY1RCNk7nFGnhIohlxIhgpzH1G3IbCkd2nS m9r5u8jc2DG+NOibrmjmvG9rhaXobCBIXTvee3WLmtxWQF9x7ybudhOh1FlWnyAiME9Yq7Kjcwh0O sU6c7OkGYw9+9AUwL4Aohgjm2vEMJHMaIMjzQPs0B3l5IjiI7WXYomBgCgeK8TzBXiUv1TJDc6D93 E2SzkYcxioGgAHCpI8AA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nySxm-0058WY-50; Tue, 07 Jun 2022 06:45:14 +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 1nySxE-0058EQ-7T; Tue, 07 Jun 2022 06:44:43 +0000 X-UUID: 217ad874c463465faf447f1c62ccdc1f-20220606 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.5,REQID:56ad6212-97e7-4b55-bde6-7868df165c00,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:7ed5e5e4-2ba2-4dc1-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: 217ad874c463465faf447f1c62ccdc1f-20220606 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 261825984; Mon, 06 Jun 2022 23:44:35 -0700 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 6 Jun 2022 23:44:34 -0700 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by mtkmbs11n1.mediatek.inc (172.21.101.185) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.792.3; Tue, 7 Jun 2022 14:44:32 +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; Tue, 7 Jun 2022 14:44:32 +0800 Message-ID: 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 , "Kishon Vijay Abraham I" , Vinod Koul , "Helge Deller" , Jitao shi CC: Markus Schneider-Pargmann , , , , , , , Date: Tue, 7 Jun 2022 14:44:32 +0800 In-Reply-To: <20220523104758.29531-19-granquet@baylibre.com> 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-20220606_234440_346299_AFFEAF19 X-CRM114-Status: GOOD ( 28.32 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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_train_handler(struct mtk_dp *mtk_dp) > +{ > + bool training_done = false; > + short max_retry = 50; > + int ret = 0; > + > + do { > + switch (mtk_dp->train_state) { > + case MTK_DP_TRAIN_STATE_STARTUP: mtk_dp->train_state is initialized as MTK_DP_TRAIN_STATE_STARTUP even though HPD ISR does not exist. Does this mean HPD ISR is redundant? If HPD ISR is not redundant, create a new state MTK_DP_TRAIN_STATE_NONE for init state. > + mtk_dp_state_handler(mtk_dp); > + mtk_dp->train_state = > MTK_DP_TRAIN_STATE_CHECKCAP; > + break; > + > + case MTK_DP_TRAIN_STATE_CHECKCAP: > + if (mtk_dp_parse_capabilities(mtk_dp)) { > + mtk_dp->train_info.check_cap_count = 0; > + mtk_dp->train_state = > MTK_DP_TRAIN_STATE_CHECKEDID; > + } else { > + mtk_dp->train_info.check_cap_count++; > + > + if (mtk_dp->train_info.check_cap_count > > > + MTK_DP_CHECK_SINK_CAP_TIMEOUT_COUNT > ) { > + mtk_dp- > >train_info.check_cap_count = 0; > + mtk_dp->train_state = > MTK_DP_TRAIN_STATE_DPIDLE; > + ret = -ETIMEDOUT; > + } > + } > + break; > + > + case MTK_DP_TRAIN_STATE_CHECKEDID: > + mtk_dp->train_state = > MTK_DP_TRAIN_STATE_TRAINING_PRE; MTK_DP_TRAIN_STATE_CHECKEDID is a redundant state, drop it. > + break; > + > + case MTK_DP_TRAIN_STATE_TRAINING_PRE: > + mtk_dp_state_handler(mtk_dp); > + mtk_dp->train_state = > MTK_DP_TRAIN_STATE_TRAINING; > + break; > + > + case MTK_DP_TRAIN_STATE_TRAINING: > + ret = mtk_dp_train_start(mtk_dp); > + if (ret == 0) { > + mtk_dp_video_mute(mtk_dp, true); > + mtk_dp->train_state = > MTK_DP_TRAIN_STATE_NORMAL; > + mtk_dp_fec_enable(mtk_dp, mtk_dp- > >has_fec); > + } else if (ret != -EAGAIN) { > + mtk_dp->train_state = > MTK_DP_TRAIN_STATE_DPIDLE; > + } > + break; > + case MTK_DP_TRAIN_STATE_NORMAL: > + mtk_dp_state_handler(mtk_dp); > + training_done = true; > + break; > + case MTK_DP_TRAIN_STATE_DPIDLE: When would this case happen? Regards, CK > + break; > + default: > + break; > + } > + > + if (ret) { > + if (ret == -EAGAIN) > + continue; > + /* > + * If we get any other error number, it doesn't > + * make any sense to keep iterating. > + */ > + break; > + } > + } while (!training_done || --max_retry); > + > + return ret; > +} _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel