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 488F7EB64DD for ; Fri, 23 Jun 2023 09:48:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231335AbjFWJr7 (ORCPT ); Fri, 23 Jun 2023 05:47:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36124 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231267AbjFWJrz (ORCPT ); Fri, 23 Jun 2023 05:47:55 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A0541A3 for ; Fri, 23 Jun 2023 02:47:54 -0700 (PDT) Received: from [IPV6:2001:b07:2ed:14ed:c5f8:7372:f042:90a2] (unknown [IPv6:2001:b07:2ed:14ed:c5f8:7372:f042:90a2]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by madras.collabora.co.uk (Postfix) with ESMTPSA id 22F9F6607136; Fri, 23 Jun 2023 10:47:52 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1687513672; bh=5xfPdsey5YOHDH601pEU4evj7XFemgGX/KLObcTGv3E=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=lGqHEpbBH6VBPV3ynNgTXGNqTtYiwGBNsQq2oQNUL9tFmx70p+4g3IagL5Gv9PDQ2 eRe2Htb0+bNAK95I8SFIkBYMay3Zaj7h65ZINYCy0ppsmfuLUVOwR3nA/Nb+VMHDxV Dx94Jnoh0zP/HtS7NwLopph0UDXQQ8+r1bBZQsMKC9P5gETWCn5MmsWgJ3YDz3ioyJ PH6EcNI+jR3BmD2DDFpvSl/b8jjyEu5e6TNwUV/qLiVeqwpVUPzfqG1B08gH8OJccS ZzZe8nAyvUS47Yn5Mx49yD0q2AwptEogsIRKc3DX3ynWVg5s5isgdU1Z6GaCZa5ljZ U5nkCdp/FHumQ== Message-ID: <735623c5-3eeb-bda3-db87-2b33d9ad3446@collabora.com> Date: Fri, 23 Jun 2023 11:47:49 +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 References: <20230523104234.7849-1-angelogioacchino.delregno@collabora.com> From: AngeloGioacchino Del Regno In-Reply-To: <20230523104234.7849-1-angelogioacchino.delregno@collabora.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 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;