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 80918CCA47F for ; Thu, 7 Jul 2022 05:14:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234808AbiGGFO6 (ORCPT ); Thu, 7 Jul 2022 01:14:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229612AbiGGFO4 (ORCPT ); Thu, 7 Jul 2022 01:14:56 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2DA031230; Wed, 6 Jul 2022 22:14:54 -0700 (PDT) X-UUID: 58f5c9dbb434497d9b99c2d6b4dd5ce6-20220707 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.8,REQID:e290d56d-f96a-4348-b372-e63675557bda,OB:0,LO B:0,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:45,FILE:0,RULE:Release_Ham,ACT ION:release,TS:45 X-CID-INFO: VERSION:1.1.8,REQID:e290d56d-f96a-4348-b372-e63675557bda,OB:0,LOB: 0,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:45,FILE:0,RULE:Release_Ham,ACTIO N:release,TS:45 X-CID-META: VersionHash:0f94e32,CLOUDID:85bfa363-0b3f-4b2c-b3a6-ed5c044366a0,C OID:687ad5be47b9,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: 58f5c9dbb434497d9b99c2d6b4dd5ce6-20220707 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 435513236; Thu, 07 Jul 2022 13:14:44 +0800 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) 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; Thu, 7 Jul 2022 13:14:43 +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; Thu, 7 Jul 2022 13:14:43 +0800 Message-ID: <6b4a4be9b5c93b1931cdbd5b009eac3bfa9badbe.camel@mediatek.com> Subject: Re: [PATCH v13 05/10] drm/mediatek: Add MT8195 Embedded DisplayPort driver From: CK Hu To: Bo-Chen Chen , , , , , , , , , , CC: , , , , , , , , , , , , Date: Thu, 7 Jul 2022 13:14:43 +0800 In-Reply-To: <20220701062808.18596-6-rex-bc.chen@mediatek.com> References: <20220701062808.18596-1-rex-bc.chen@mediatek.com> <20220701062808.18596-6-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-kernel@vger.kernel.org Hi, Bo-Chen: On Fri, 2022-07-01 at 14:28 +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 ssize_t mtk_dp_hpd_sink_event(struct mtk_dp *mtk_dp) The caller never use the return value, so let this function to void. > +{ > + ssize_t ret; > + u8 sink_count; > + 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); You read sink_count but never use it, so this read is redundant. Remove it. > + if (ret < 1) { > + drm_err(mtk_dp->drm_dev, "Read sink count failed\n"); > + return ret == 0 ? -EIO : 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\n"); > + return ret; > + } > + > + drm_dp_channel_eq_ok(link_status, mtk_dp- > >train_info.lane_count); This function just return true or false, and you does not process the return value, so this is redundant. Remove it. Regard, CK > + > + 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); > + > + return 0; > +}