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 7ED39C5B572 for ; Sun, 16 Aug 2026 12:56:16 +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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Message-ID:MIME-Version:References: In-Reply-To:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=7U3p3BsN7dXRwt+GIcoAQmtZcGbmCYoPNwm4lc9pSU4=; b=nmTCPVV1RS8CKM hTx869Uty1Pb0EChE4XtLXOKgD4tAvYNs0f6a1RytBYgtOj4s2BSw603piYFfmGduthdQOD/ESZlv tPP9lSo2bla7YyIRo80lNER8DaXAmtGEptbG39Lc0uofxYFOcmFoHiFtLsA6nuwvfLdUmwyvvtigD yRqJy1ortxLcybXu4I03+O4KPhBX4C8dulkswYQ8n+381HZLz9BWZErK2quXiZQS61AK2WexHw4hL OtYATc+NMNpNdWvOwoxB/s0ukcWiVr1hkVRpuSPsL34Q4wlXGh/Y6T+hnKxEe4QV8VA7jTCqUGR06 v/fUZQQMUKhBQwM8dUWg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wvaPO-00000004mDo-0IZE; Sun, 16 Aug 2026 12:56:14 +0000 Received: from m16.mail.163.com ([117.135.210.5]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wvaPL-00000004mDP-1SAo; Sun, 16 Aug 2026 12:56:13 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Date:From:To:Subject:Content-Type:MIME-Version: Message-ID; bh=KtM92UjDWiVOHakM71uJ+Lae20Hh7YTTnG8gbjrvN4k=; b=I p5D4QiZkvxVOThYHJkbd4nJ92vidSeFLJw7tML2sNZY6o8SW4ctg6/o2ne6ie/WL VFLliQTsGgzzhWhtVegwsvfLyz3/Gd3dRRPhvsZ2I5VtpvBn4fVsi91axe8mRbIi CwY5sLxjdrursXz4gqRVdF8r20UNXUK5mtbRTwvWro= Received: from andyshrk$163.com ( [61.154.14.86] ) by ajax-webmail-wmsvr-40-100 (Coremail) ; Sun, 16 Aug 2026 20:54:39 +0800 (CST) X-Originating-IP: [61.154.14.86] Date: Sun, 16 Aug 2026 20:54:39 +0800 (CST) From: "Andy Yan" To: "Sebastian Reichel" Subject: Re:[PATCH v11 07/21] drm/bridge: synopsys: dw-dp: Fix support for short I2C reads X-Priority: 3 X-Mailer: Coremail Webmail Server Version 2023.4-cmXT build 20260511(2e539873) Copyright (c) 2002-2026 www.mailtech.cn 163com In-Reply-To: <20260806-synopsys-dw-dp-improvements-v11-7-0d508505f383@collabora.com> References: <20260806-synopsys-dw-dp-improvements-v11-0-0d508505f383@collabora.com> <20260806-synopsys-dw-dp-improvements-v11-7-0d508505f383@collabora.com> X-NTES-SC: AL_Qu2TBPSTu0As7yCcZekfmUgWjuw/WsG1v/Ul1YBSP556jCrp6yoHelRJMXX9zsmrEg+xlzSHfCNT0M9dRK11eZMXRPYLCgc9i8hWgKKkem2vbA== MIME-Version: 1.0 Message-ID: <2c10a52.193c.1a00aa372c7.Coremail.andyshrk@163.com> X-Coremail-Locale: zh_CN X-CM-TRANSID: ZCgvCgD33xwPs4Fqy8cyAA--.25160W X-CM-SenderInfo: 5dqg52xkunqiywtou0bp/xtbCxg-qSWqBsw-x+gAA32 X-Coremail-Antispam: 1U5529EdanIXcx71UUUUU7vcSsGvfC2KfnxnUU== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260816_055612_190257_DBC01FFB X-CRM114-Status: UNSURE ( 9.30 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?UTF-8?Q?Heiko_St=C3=BCbner?= , Sashiko , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Laurent Pinchart , Andrzej Hajda , kernel@collabora.com, David Airlie , Simona Vetter , Rob Herring , Robert Foss , Jernej Skrabec , linux-rockchip@lists.infradead.org, Luca Ceresoli , devicetree@vger.kernel.org, Conor Dooley , Thomas Zimmermann , Jonas Karlman , Maarten Lankhorst , Maxime Ripard , Alexey Charkov , Damon Ding , linux-arm-kernel@lists.infradead.org, Dmitry Baryshkov , Neil Armstrong , Dmitry Baryshkov , Sandy Huang , Philipp Zabel , Andy Yan , Krzysztof Kozlowski Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org Hello Sebastian, At 2026-08-07 01:02:13, "Sebastian Reichel" wrote: >The transfer functions returns the amount of bytes read for >DP_AUX_I2C_READ. By returning -EBUSY for short reads, the caller has >less information available what is going wrong and possibly simply >resends the read request. On sinks not supporting long reads, this will >simply run into the same issue again. > >Instead it makes more sense to return the data from the short read with >the length information, which allows drm_dp_i2c_do_msg() to read data in >smaller chunks and succeed in the end. > >Due to lack of a sink, which only supports short reads, this change is >effectively untested. > >Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library") >Reported-by: Sashiko >Signed-off-by: Sebastian Reichel Reviewed-by: Andy Yan >--- > drivers/gpu/drm/bridge/synopsys/dw-dp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c >index 2573ea2bb574..8ceb139f1a72 100644 >--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c >+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c >@@ -1513,7 +1513,7 @@ static ssize_t dw_dp_aux_transfer(struct drm_dp_aux *aux, > if (msg->request & DP_AUX_I2C_READ) { > size_t count = FIELD_GET(AUX_BYTES_READ, value) - 1; > >- if (count != msg->size) >+ if (!count || count > msg->size) > return -EBUSY; > > ret = dw_dp_aux_read_data(dp, msg->buffer, count); > >-- >2.53.0 _______________________________________________ Linux-rockchip mailing list Linux-rockchip@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-rockchip