From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-202.mailbox.org (mout-p-202.mailbox.org [80.241.56.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 99F7B3A0B2C; Fri, 27 Feb 2026 10:41:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772188881; cv=none; b=bJiIP9KOp8zVXoDo2nIcgMjVzuzAfhkxiHjmJy0fGMhnh+HiSf7piOVacXG6PtQ6GlCR3N+6edvKJsfrfKUc2Ah1JthwnSuDnRqJ+vvQMHM/9WToAMSCOIPYRGF5Ao9cBjLz2l8bh3ZTT0LFaA+TlSPjaMJtD9Gc5O0yyAmHCmk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772188881; c=relaxed/simple; bh=hA6BDFZd6MrTqTGLDzBaPrfAhnfCTTQ+7BKj1oIHx4M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=r36coEtkBcirLJQ4+oU9SSkpx7vPyOSF0SmzC+1uK7RN451C3aYL74OW//9Nhvjb1ejV5L3wAUztZ3yA8tsB3Zrjic4HZ5F6GtVzJEaIHpjMSp8AQP0BlG8UCVjGhN/QkwYdWWcgKQ5XNmYmSh0PJUq44B7jkcAlD54hArPSc9I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=hiX3S0gD; arc=none smtp.client-ip=80.241.56.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="hiX3S0gD" Received: from smtp202.mailbox.org (smtp202.mailbox.org [10.196.197.202]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-202.mailbox.org (Postfix) with ESMTPS id 4fMlHH73q0z9sZZ; Fri, 27 Feb 2026 11:41:15 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1772188876; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=a8yNHrrv8hSbIol16MyTEr4gp82KA1j7w7oSm0UgB4U=; b=hiX3S0gD7vIoc4g2amN34KUBr/5pehQhklGW8kRGIc/fmgEwPBDYzNOFwjY1iXF5ultF2K eOnxr4WSwbotJ5DQI+g+VUeH+5TgK/J+t7nO0erjf7VAeMGPvcpr9vKQxI3lZJxnLiE7ri PLjjZe9+yXiFHUeyvB7fs68OaOaqkt51G4zBDoxLmO3WxzGPeMqSVra4N2eMLF2jWrz60i dGq/WMv7TUKtcEdgodDdG3XkkVZrifQngq6k43rzwVG5JVa250UQDB7IDmb2frjg4f4xXU bdRW2LTA6aujo3dmf82hpg3vp38iFh0xrZN/jqgmgHrsXDwcaEtzvu9CyvdwwQ== Message-ID: <4b796cc7-bf3d-4eb1-8e29-33e90851c34d@mailbox.org> Date: Fri, 27 Feb 2026 11:41:10 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH 2/3] drm/bridge: ti-sn65dsi83: halve horizontal syncs for dual LVDS output To: Luca Ceresoli , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Frieder Schrempf , Linus Walleij Cc: Thomas Petazzoni , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20260226-ti-sn65dsi83-dual-lvds-fixes-and-test-pattern-v1-0-2e15f5a9a6a0@bootlin.com> <20260226-ti-sn65dsi83-dual-lvds-fixes-and-test-pattern-v1-2-2e15f5a9a6a0@bootlin.com> Content-Language: en-US From: Marek Vasut In-Reply-To: <20260226-ti-sn65dsi83-dual-lvds-fixes-and-test-pattern-v1-2-2e15f5a9a6a0@bootlin.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-MBO-RS-ID: cba5140bc5ed835239e X-MBO-RS-META: rinne88hpm9po5saewn6i3bhefqz3wx7 On 2/26/26 5:16 PM, Luca Ceresoli wrote: > Dual LVDS output (available on the SN65DSI84) requires HSYNC_PULSE_WIDTH > and HORIZONTAL_BACK_PORCH to be divided by two with respect to the values > used for single LVDS output. > > While not clearly stated in the datasheet, this is needed according to the > DSI Tuner [0] output. It also makes sense intuitively because in dual LVDS > output two pixels at a time are output and so the output clock is half of > the pixel clock. > > Some dual-LVDS panels refuse to show any picture without this fix. > > Divide by two HORIZONTAL_FRONT_PORCH too, even though this register is used > only for test pattern generation which is not currently implemented by this > driver. Reviewed-by: Marek Vasut Thanks !