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 D0977C54EBD for ; Mon, 9 Jan 2023 11:27:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236808AbjAIL0s (ORCPT ); Mon, 9 Jan 2023 06:26:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236943AbjAIL0a (ORCPT ); Mon, 9 Jan 2023 06:26:30 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A133C183A8 for ; Mon, 9 Jan 2023 03:26:29 -0800 (PST) Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) (Authenticated sender: kholk11) by madras.collabora.co.uk (Postfix) with ESMTPSA id B08936602D06; Mon, 9 Jan 2023 11:26:27 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1673263588; bh=eKJGPDGPsYgrZbdxBcghst0mxz5CKz2aEmqkcsFMp14=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=I4DJgybrdIjRLeS4QFB7meP/vAkmLJN70/VBJI1/OhW5BJTVhmCyMP3VL4GF7Moj8 a9XUTsyt2ElGO8U6/lQDZ4R/ccAvcryCWG4rYQgsRuFSEWVX6X/bf5nDu+gKArEj1G jkylAl/Fy4EnC6e5Mh50HvrYlzJEBfN5QB5Y3IoYWcVO5YDfFbtL4cp/J+iq9ysU4b mXGEsh97WiYCwqrPVZHgVa3ekJyAmz0dclzk+GipxatfRm6AaVxBXsb/YFUnniEvIb NQ/8nHRXRZLMmfAa++YM+NBs0ikvpBphHVvFz2GXCRkxsepS51H7ov8B9KebeP+fSS LIc6YNjFG8J4w== Message-ID: Date: Mon, 9 Jan 2023 12:26:24 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH 1/2] drm/mediatek: dsi: Reduce the time of dsi from LP11 to sending cmd To: xinlei.lee@mediatek.com, chunkuang.hu@kernel.org, p.zabel@pengutronix.de, airlied@linux.ie, daniel@ffwll.ch, matthias.bgg@gmail.com, jitao.shi@mediatek.com, thierry.reding@gmail.com, sam@ravnborg.org Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Project_Global_Chrome_Upstream_Group@mediatek.com References: <1672974321-18947-1-git-send-email-xinlei.lee@mediatek.com> <1672974321-18947-2-git-send-email-xinlei.lee@mediatek.com> Content-Language: en-US From: AngeloGioacchino Del Regno In-Reply-To: <1672974321-18947-2-git-send-email-xinlei.lee@mediatek.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 06/01/23 04:05, xinlei.lee@mediatek.com ha scritto: > From: Xinlei Lee > > According to Figure 16 Turnaround Procedure on page 36 in [1], you > can see the status of LP-00 -> LP10 -> LP11. This state can correspond > to the state of DSI from LP00 -> LP11 in mtk_dsi_lane_ready function > in mtk_dsi.c. > > LP-00 -> LP10 -> LP11 takes about 2*TLPX time (refer to [1] page 51 > to see that TLPX is 50ns). > > The delay at the end of the mtk_dsi_lane_ready function should be > greater than the 2*TLPX specified by the DSI spec, and less than > the time specified by the DSI_RX (generally 6ms to 40ms), to avoid > problems caused by the RX specification. > > [1]:mipi_D-PHY_specification_v1-1 > > Fixes: 39e8d062b03c ("drm/mediatek: Keep dsi as LP00 before dcs cmds transfer") > Signed-off-by: Xinlei Lee Reviewed-by: AngeloGioacchino Del Regno