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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5B23C433DF for ; Tue, 30 Jun 2020 11:45:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C62B2207F9 for ; Tue, 30 Jun 2020 11:45:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730955AbgF3Lo7 (ORCPT ); Tue, 30 Jun 2020 07:44:59 -0400 Received: from asavdk4.altibox.net ([109.247.116.15]:43102 "EHLO asavdk4.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733050AbgF3Lo6 (ORCPT ); Tue, 30 Jun 2020 07:44:58 -0400 Received: from ravnborg.org (unknown [188.228.123.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by asavdk4.altibox.net (Postfix) with ESMTPS id 738CA804B4; Tue, 30 Jun 2020 13:44:54 +0200 (CEST) Date: Tue, 30 Jun 2020 13:44:53 +0200 From: Sam Ravnborg To: Paul Cercueil Cc: David Airlie , Daniel Vetter , Rob Herring , devicetree@vger.kernel.org, linux-mips@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, od@zcrc.me Subject: Re: [PATCH v2 06/10] drm/ingenic: Set DMA descriptor chain address in probe Message-ID: <20200630114453.GB560155@ravnborg.org> References: <20200629235210.441709-1-paul@crapouillou.net> <20200629235210.441709-6-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200629235210.441709-6-paul@crapouillou.net> X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=aP3eV41m c=1 sm=1 tr=0 a=S6zTFyMACwkrwXSdXUNehg==:117 a=S6zTFyMACwkrwXSdXUNehg==:17 a=kj9zAlcOel0A:10 a=ER_8r6IbAAAA:8 a=e5mUnYsNAAAA:8 a=_F4ZNtTwmw7fjDG2MVkA:9 a=7tZkzEg-RNLL3d5o:21 a=j8Rw1sZxBYetKqRA:21 a=CjuIK1q_8ugA:10 a=9LHmKk7ezEChjTCyhBa9:22 a=Vxmtnl_E_bksehYqCbjh:22 a=pHzHmUro8NiASowvMSCR:22 a=nt3jZW36AmriUCFCBwmW:22 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Paul. On Tue, Jun 30, 2020 at 01:52:06AM +0200, Paul Cercueil wrote: > The address of the DMA descriptor never changes. It can therefore be set > in the probe function. > > Signed-off-by: Paul Cercueil > --- > > Notes: > v2: No change > > drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c > index 924c8daf071a..f7b0c5dc8cd8 100644 > --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c > +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c > @@ -358,8 +358,6 @@ static void ingenic_drm_crtc_atomic_flush(struct drm_crtc *crtc, > ingenic_drm_crtc_update_ctrl(priv, finfo); > > clk_set_rate(priv->pix_clk, state->adjusted_mode.clock * 1000); > - > - regmap_write(priv->map, JZ_REG_LCD_DA0, priv->dma_hwdesc->next); > } > > if (event) { > @@ -757,6 +755,9 @@ static int ingenic_drm_probe(struct platform_device *pdev) > } > } > > + /* Set address of our DMA descriptor chain */ > + regmap_write(priv->map, JZ_REG_LCD_DA0, priv->dma_hwdesc_phys); > + What is the purpose of this code after the assignment was moved: static int ingenic_drm_probe(struct platform_device *pdev) { ... priv->dma_hwdesc->next = priv->dma_hwdesc_phys; I do not see ->next used anymore. Could this assignment be dropped? And the following line: priv->dma_hwdesc->id = 0xdeafbead; I can only see ->id be assingned, it is never referenced?? Maybe this is all related to the structure assumed by the data pointed to by JZ_REG_LCD_DA0? Sam > ret = drm_dev_register(drm, 0); > if (ret) { > dev_err(dev, "Failed to register DRM driver\n"); > -- > 2.27.0 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel