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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 12E39C48BD3 for ; Wed, 26 Jun 2019 13:32:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB0DF205ED for ; Wed, 26 Jun 2019 13:32:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727841AbfFZNcm (ORCPT ); Wed, 26 Jun 2019 09:32:42 -0400 Received: from inva021.nxp.com ([92.121.34.21]:57602 "EHLO inva021.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727776AbfFZNcb (ORCPT ); Wed, 26 Jun 2019 09:32:31 -0400 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id DEFAA2009A8; Wed, 26 Jun 2019 15:32:28 +0200 (CEST) Received: from inva024.eu-rdc02.nxp.com (inva024.eu-rdc02.nxp.com [134.27.226.22]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id D1C802009B2; Wed, 26 Jun 2019 15:32:28 +0200 (CEST) Received: from fsr-ub1664-120.ea.freescale.net (fsr-ub1664-120.ea.freescale.net [10.171.82.81]) by inva024.eu-rdc02.nxp.com (Postfix) with ESMTP id 24DA1205DB; Wed, 26 Jun 2019 15:32:28 +0200 (CEST) From: Robert Chiras To: Marek Vasut , Stefan Agner , David Airlie , Daniel Vetter , Rob Herring , Mark Rutland , Shawn Guo , Sascha Hauer , Fabio Estevam Cc: Pengutronix Kernel Team , NXP Linux Team , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Robert Chiras Subject: [PATCH 09/10] drm/mxsfb: Clear OUTSTANDING_REQS bits Date: Wed, 26 Jun 2019 16:32:17 +0300 Message-Id: <1561555938-21595-10-git-send-email-robert.chiras@nxp.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1561555938-21595-1-git-send-email-robert.chiras@nxp.com> References: <1561555938-21595-1-git-send-email-robert.chiras@nxp.com> X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Bit 21 can alter the CTRL2_OUTSTANDING_REQS value right after the eLCDIF is enabled, since it comes up with default value of 1 (this behaviour has been seen on some imx8 platforms). In order to fix this, clear CTRL2_OUTSTANDING_REQS bits before setting its value. Signed-off-by: Robert Chiras --- drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c index 45ca16b..02a5684 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c @@ -223,7 +223,14 @@ static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb) clk_prepare_enable(mxsfb->clk); if (mxsfb->devdata->ipversion >= 4) { - writel(CTRL2_OUTSTANDING_REQS__REQ_16, + /* + * On some platforms, bit 21 is defaulted to 1, which may alter + * the below setting. So, to make sure we have the right setting + * clear all the bits for CTRL2_OUTSTANDING_REQS. + */ + writel(CTRL2_OUTSTANDING_REQS(0x7), + mxsfb->base + LCDC_V4_CTRL2 + REG_CLR); + writel(CTRL2_OUTSTANDING_REQS(REQ_16), mxsfb->base + LCDC_V4_CTRL2 + REG_SET); /* Assert LCD Reset bit */ writel(CTRL2_LCD_RESET, mxsfb->base + LCDC_V4_CTRL2 + REG_SET); -- 2.7.4