From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752376AbeDKId6 (ORCPT ); Wed, 11 Apr 2018 04:33:58 -0400 Received: from mail-it0-f67.google.com ([209.85.214.67]:35134 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751870AbeDKId4 (ORCPT ); Wed, 11 Apr 2018 04:33:56 -0400 X-Google-Smtp-Source: AIpwx4//zpnzrddpE2RHTf688CFD/OiQ5DgtVQY0exfImZntl3ufrOPVXutmQlBUTCruEK5fsEag2A== From: Jia-Ju Bai To: architt@codeaurora.org, a.hajda@samsung.com, Laurent.pinchart@ideasonboard.com, airlied@linux.ie, daniel.vetter@ffwll.ch, bhumirks@gmail.com, narmstrong@baylibre.com, inki.dae@samsung.com Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] gpu: drm: bridge: adv7511: Replace mdelay with usleep_range in adv7511_probe Date: Wed, 11 Apr 2018 16:33:42 +0800 Message-Id: <1523435622-4329-1-git-send-email-baijiaju1990@gmail.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 adv7511_probe() is never called in atomic context. This function is only set as ".probe" in struct i2c_driver. Despite never getting called from atomic context, adv7511_probe() calls mdelay() to busily wait. This is not necessary and can be replaced with usleep_range() to avoid busy waiting. This is found by a static analysis tool named DCNS written by myself. And I also manually check it. Signed-off-by: Jia-Ju Bai --- drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index b2431ae..2cf7fa1 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1054,7 +1054,7 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id) } if (adv7511->gpio_pd) { - mdelay(5); + usleep_range(5000, 6000); gpiod_set_value_cansleep(adv7511->gpio_pd, 0); } -- 1.9.1