From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932671AbcECCYP (ORCPT ); Mon, 2 May 2016 22:24:15 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:36261 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932239AbcECCYO (ORCPT ); Mon, 2 May 2016 22:24:14 -0400 From: Caesar Wang To: edubezval@gmail.com Cc: rui.zhang@intel.com, heiko@sntech.de, linux-rockchip@lists.infradead.org, huangtao@rock-chips.com, Caesar Wang , linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] thermal: rockchip: use the usleep_range instead of udelay Date: Tue, 3 May 2016 10:23:50 +0800 Message-Id: <1462242230-20873-1-git-send-email-wxt@rock-chips.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Documentation/timers/timers-howto.txt recommends to use usleep_range on delays > 10usec. The usleep_range indeed reduces CPU load, since the udelay will busy wait for enough loop cycles to achieve the desired delay. Fixes commit b06c52db39fd ("thermal: rockchip: handle the power sequence for tsadc controller"). Cc: Zhang Rui Cc: Eduardo Valentin Cc: Heiko Stuebner Suggested-by: Eduardo Valentin Signed-off-by: Caesar Wang --- drivers/thermal/rockchip_thermal.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c index 86a1ab0..5d491f1 100644 --- a/drivers/thermal/rockchip_thermal.c +++ b/drivers/thermal/rockchip_thermal.c @@ -547,10 +547,10 @@ static void rk_tsadcv3_initialize(struct regmap *grf, void __iomem *regs, regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_ON); mdelay(10); regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_OFF); - udelay(100); /* The spec note says at least 15 us */ + usleep_range(15, 100); /* The spec note says at least 15 us */ regmap_write(grf, GRF_SARADC_TESTBIT, GRF_SARADC_TESTBIT_ON); regmap_write(grf, GRF_TSADC_TESTBIT_H, GRF_TSADC_TESTBIT_H_ON); - udelay(200); /* The spec note says at least 90 us */ + usleep_range(90, 200); /* The spec note says at least 90 us */ } if (tshut_polarity == TSHUT_HIGH_ACTIVE) -- 1.9.1