From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753881AbcIFEC5 (ORCPT ); Tue, 6 Sep 2016 00:02:57 -0400 Received: from mail.kmu-office.ch ([178.209.48.109]:34895 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753454AbcIFECy (ORCPT ); Tue, 6 Sep 2016 00:02:54 -0400 From: Stefan Agner To: dri-devel@lists.freedesktop.org, meng.yi@nxp.com Cc: alison.wang@freescale.com, jianwei.wang.chn@gmail.com, linux-kernel@vger.kernel.org, Stefan Agner Subject: [PATCH 4/4] drm/fsl-dcu: do not update when modifying irq registers Date: Mon, 5 Sep 2016 21:02:33 -0700 Message-Id: <20160906040233.32471-5-stefan@agner.ch> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20160906040233.32471-1-stefan@agner.ch> References: <20160906040233.32471-1-stefan@agner.ch> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The IRQ status and mask registers are not "double buffered" according to the reference manual. Hence, there is no extra transfer/update write needed when modifying these registers. Signed-off-by: Stefan Agner --- drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c index 092aaec..4e700bc4 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c @@ -59,8 +59,6 @@ static int fsl_dcu_drm_irq_init(struct drm_device *dev) regmap_write(fsl_dev->regmap, DCU_INT_STATUS, 0); regmap_write(fsl_dev->regmap, DCU_INT_MASK, ~0); - regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE, - DCU_UPDATE_MODE_READREG); return ret; } @@ -139,8 +137,6 @@ static irqreturn_t fsl_dcu_drm_irq(int irq, void *arg) drm_handle_vblank(dev, 0); regmap_write(fsl_dev->regmap, DCU_INT_STATUS, int_status); - regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE, - DCU_UPDATE_MODE_READREG); return IRQ_HANDLED; } -- 2.9.3