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 257AFC624DE for ; Fri, 4 Sep 2026 08:32:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=MzSSeYpgZ1cl36kwxauq490fq+r6qAsAHJo6BhOSQ1w=; b=QRXlOm52MM8ZJ5sHHcSUWHCaqB TXv8c1EJfDx8DeQgm+MhEap6fsLZ5+odTDT8AfROOJDjXZDlqJaYWeWASASG7Fz4rkW4ZejTuZecW guk7DWb3dvR44O+1md0mXlzO3ukBbi+elHPpNPVM/aKxdm+p2OqCjEC+r6Z18tYx6bNGKTIjIGhkS mU+0hKyq6PUyaYuZWca+t6TafF3ieywW+25JJKWZDJxjPoh3ZFBd8kEKgVMEIypWmeFcrIWtHbLcQ uiksqnV4WAw6t3ZceGLSnVVvvU/h4iVfLRZQaPgMyaTuYvmAHZR4Jc6907Oyodd5etjWpVxA7LSyU oXhcsPSg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x2PLj-00000001NhJ-40pA; Fri, 04 Sep 2026 08:32:39 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x2PLj-00000001Nh0-0CCO for linux-arm-kernel@lists.infradead.org; Fri, 04 Sep 2026 08:32:39 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id B957D43716; Fri, 4 Sep 2026 08:32:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20F681F00A3D; Fri, 4 Sep 2026 08:32:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788510758; bh=MzSSeYpgZ1cl36kwxauq490fq+r6qAsAHJo6BhOSQ1w=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=JFYXZymr1wFshuxLBjvl/iyhixHCkCSdNKcEN4AdpqHPjeNe7OCTSE9W9hyu9xtuR /THPX4vBmSvJmF3/ZEUA0Da+o6/SwDv3VnW8nLLZ1vZUXCYX7XSUIRIpRRy20QtS1p LF6EVoW/ugz7TlGexEb7v2M4BXLeUpHamQwlImMuJSyCceHzASAiMD7tjzJyLw4U0g oQbNYEnp/4CefBvHa+Q+hpYns3elxf245Bc+SIoPF6gG8PcFbHVPHbmm+dQLvN3+G8 g/YEenlDO0dhAt+Ykn56tIdGC+h71gO4vAjFXu8vxm5d3fHugsZfydYpcumgCDAsZ1 Qwq7tPZZNOoKQ== Date: Fri, 4 Sep 2026 10:32:35 +0200 From: Maxime Ripard To: Liu Ying Cc: Philipp Zabel , Maarten Lankhorst , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Dmitry Baryshkov , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Marek Vasut , Frank Li Subject: Re: [PATCH v6 07/13] drm/imx: dc: Use TCON operation mode Message-ID: References: <20260904-imx8-dc-prefetch-v6-0-26643e3f6cb7@nxp.com> <20260904-imx8-dc-prefetch-v6-7-26643e3f6cb7@nxp.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha384; protocol="application/pgp-signature"; boundary="xjuaddo6esktd3cx" Content-Disposition: inline In-Reply-To: <20260904-imx8-dc-prefetch-v6-7-26643e3f6cb7@nxp.com> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --xjuaddo6esktd3cx Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Subject: Re: [PATCH v6 07/13] drm/imx: dc: Use TCON operation mode MIME-Version: 1.0 Hi, On Fri, Sep 04, 2026 at 03:54:57PM +0800, Liu Ying wrote: > @@ -273,7 +285,22 @@ dc_crtc_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_commit *state) > dc_ed_pec_sync_trigger(dc_crtc->ed_cont); > dc_ed_pec_sync_trigger(dc_crtc->ed_safe); > dc_fg_shdtokgen(dc_crtc->fg); > + > + /* Don't relinquish CPU until TCON is set to operation mode. */ > + local_irq_save(flags); > + preempt_disable(); > + > dc_fg_enable(dc_crtc->fg); > + /* > + * Turn TCON into operation mode as soon as the first dumb > + * frame is generated by DC(we don't relinquish CPU to ensure > + * this). This makes DPR/PRG be able to evade the frame. > + */ > + DC_CRTC_WAIT_FOR_FRAMEGEN_FRAME_INDEX_MOVING(dc_crtc->fg); > + dc_tc_set_operation_mode(dc_crtc->tc); > + > + local_irq_restore(flags); > + preempt_enable(); That's really not great... Can you expand on why you need this, and is there really no other way to do it? Maxime --xjuaddo6esktd3cx Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iJUEABMJAB0WIQTkHFbLp4ejekA/qfgnX84Zoj2+dgUCapqCIgAKCRAnX84Zoj2+ dir1AYCXpT5cVplY44dNchFSkeexJ/EEll6WarzurZvlyuK4ccEsQLN5u16HB+0M d69UP2sBfR04gGdJ/dhDGLj+kSe/MOJTZ8fjbbkfK0hpumFAmqrpXyNhp/ODKajZ YtkzHwfDPg== =7yGx -----END PGP SIGNATURE----- --xjuaddo6esktd3cx--