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 1F10FEB64DA for ; Wed, 19 Jul 2023 07:39:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229596AbjGSHjx (ORCPT ); Wed, 19 Jul 2023 03:39:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229471AbjGSHjv (ORCPT ); Wed, 19 Jul 2023 03:39:51 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B313E43 for ; Wed, 19 Jul 2023 00:39:50 -0700 (PDT) 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 762EB660704A; Wed, 19 Jul 2023 08:39:48 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1689752389; bh=rNVjWyGyb4/QZCXHyXWf5MRLedoD5uQC2pGcS2nQLJM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=KXAnIw+qjtq/TVA5eamsTuqS52g5ZYSbnDDs6DVc9VL/h9OMKBeFUUOoaNERSSpeV u1iFRJZg59z7AUj8yplJ80OnLpIUBGZ0EdYaO29XIB+ZMEf3f1yHGV3VfzkWA0mTFA IWnJwDSjAdrErnMtvJkaKkiTnBil+eBYIsnBgvU17ETesA9N1A76livi2XS6bwsneT krC2W+oSTYwET1WjqEeJRAp7nDKZ+ngg193F2j24GMpCm/WfJvSlGmo0z+l6XQVpIU ntX7vGSmW6rVD3taA6mIJowkm7Ppt588Jlw/74A+v3YLXlxCwZwORhaLSC+bNkWvND WM6Oz3TI9R6pg== Message-ID: <07c93d61-c5fd-f074-abb2-73fdaa81fd65@collabora.com> Date: Wed, 19 Jul 2023 09:39:45 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH] drm: mediatek: mtk_dsi: Fix NO_EOT_PACKET settings/handling Content-Language: en-US To: chunkuang.hu@kernel.org Cc: p.zabel@pengutronix.de, airlied@gmail.com, daniel@ffwll.ch, matthias.bgg@gmail.com, jitao.shi@mediatek.com, ck.hu@mediatek.com, shaoming.chen@mediatek.com, yt.shen@mediatek.com, dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Alexandre Mergnat References: <20230523104234.7849-1-angelogioacchino.delregno@collabora.com> <735623c5-3eeb-bda3-db87-2b33d9ad3446@collabora.com> <2f1d4e6b-bf03-25d1-dac2-83e0dbd5734f@baylibre.com> From: AngeloGioacchino Del Regno In-Reply-To: <2f1d4e6b-bf03-25d1-dac2-83e0dbd5734f@baylibre.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 23/06/23 13:29, Alexandre Mergnat ha scritto: > > > On 23/06/2023 11:47, AngeloGioacchino Del Regno wrote: >> Il 23/05/23 12:42, AngeloGioacchino Del Regno ha scritto: >>> Due to the initial confusion about MIPI_DSI_MODE_EOT_PACKET, properly >>> renamed to MIPI_DSI_MODE_NO_EOT_PACKET, reflecting its actual meaning, >>> both the DSI_TXRX_CON register setting for bit (HSTX_)DIS_EOT and the >>> later calculation for horizontal sync-active (HSA), back (HBP) and >>> front (HFP) porches got incorrect due to the logic being inverted. >>> >>> This means that a number of settings were wrong because....: >>>   - DSI_TXRX_CON register setting: bit (HSTX_)DIS_EOT should be >>>     set in order to disable the End of Transmission packet; >>>   - Horizontal Sync and Back/Front porches: The delta used to >>>     calculate all of HSA, HBP and HFP should account for the >>>     additional EOT packet. >>> >>> Before this change... >>>   - Bit (HSTX_)DIS_EOT was being set when EOT packet was enabled; >>>   - For HSA/HBP/HFP delta... all three were wrong, as words were >>>     added when EOT disabled, instead of when EOT packet enabled! >>> >>> Invert the logic around flag MIPI_DSI_MODE_NO_EOT_PACKET in the >>> MediaTek DSI driver to fix the aforementioned issues. >>> >>> Fixes: 8b2b99fd7931 ("drm/mediatek: dsi: Fine tune the line time caused by EOTp") >>> Fixes: 2d52bfba09d1 ("drm/mediatek: add non-continuous clock mode and EOT packet >>> control") >>> Signed-off-by: AngeloGioacchino Del Regno >> >> Gentle ping for an important fix. >> >> Regards, >> Angelo >> >>> --- >>>   drivers/gpu/drm/mediatek/mtk_dsi.c | 4 ++-- >>>   1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c >>> b/drivers/gpu/drm/mediatek/mtk_dsi.c >>> index 7d5250351193..b0ab38e59db9 100644 >>> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c >>> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c >>> @@ -407,7 +407,7 @@ static void mtk_dsi_rxtx_control(struct mtk_dsi *dsi) >>>       if (dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) >>>           tmp_reg |= HSTX_CKLP_EN; >>> -    if (!(dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)) >>> +    if (dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET) >>>           tmp_reg |= DIS_EOT; >>>       writel(tmp_reg, dsi->regs + DSI_TXRX_CTRL); >>> @@ -484,7 +484,7 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi) >>>                 timing->da_hs_zero + timing->da_hs_exit + 3; >>>       delta = dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST ? 18 : 12; >>> -    delta += dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET ? 2 : 0; >>> +    delta += dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET ? 0 : 2; >>>       horizontal_frontporch_byte = vm->hfront_porch * dsi_tmp_buf_bpp; >>>       horizontal_front_back_byte = horizontal_frontporch_byte + >>> horizontal_backporch_byte; >> >> > > Sounds logic > > Reviewed-by: Alexandre Mergnat > Ping again. Regards, Angelo