From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753705AbeAZPOp (ORCPT ); Fri, 26 Jan 2018 10:14:45 -0500 Received: from mail-pg0-f67.google.com ([74.125.83.67]:43475 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753687AbeAZPOl (ORCPT ); Fri, 26 Jan 2018 10:14:41 -0500 X-Google-Smtp-Source: AH8x225Abc06ixO1xVA3Vc58JzF6yJTSqN/ufBke+xsYvVO/SKLRo+0ntXkigw1gsgX33ED6rVdK/Q== From: Jia-Ju Bai To: miguel.ojeda.sandonis@gmail.com, w@1wt.eu Cc: linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] auxdisplay: charlcd: delete mdelay in long_sleep Date: Fri, 26 Jan 2018 23:19:15 +0800 Message-Id: <1516979955-7466-1-git-send-email-baijiaju1990@gmail.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The function long_sleep() calls mdelay() when in an interrupt handler. But only charlcd_clear_display() and charlcd_init_display calls long_sleep(), and my tool finds that the two functions are never called in an interrupt handler. Thus mdelay() and in_interrupt() are not necessary. This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai --- drivers/auxdisplay/charlcd.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c index 642afd8..9e84795 100644 --- a/drivers/auxdisplay/charlcd.c +++ b/drivers/auxdisplay/charlcd.c @@ -102,10 +102,7 @@ struct charlcd_priv { /* sleeps that many milliseconds with a reschedule */ static void long_sleep(int ms) { - if (in_interrupt()) - mdelay(ms); - else - schedule_timeout_interruptible(msecs_to_jiffies(ms)); + schedule_timeout_interruptible(msecs_to_jiffies(ms)); } /* turn the backlight on or off */ -- 1.7.9.5