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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 E5697C79F80 for ; Fri, 4 Sep 2026 08:32:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2138A10F95C; Fri, 4 Sep 2026 08:32:41 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="JFYXZymr"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 24B4E10F95C for ; Fri, 4 Sep 2026 08:32:39 +0000 (UTC) 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: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --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--