From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752380AbeAZPhv (ORCPT ); Fri, 26 Jan 2018 10:37:51 -0500 Received: from mail-pg0-f67.google.com ([74.125.83.67]:42244 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751431AbeAZPht (ORCPT ); Fri, 26 Jan 2018 10:37:49 -0500 X-Google-Smtp-Source: AH8x2250OTWLOl0/EvV5qx6QbaFWyj1w+Hhyu8auGviQ7XE/ZPfVeKWvN++y1Fww2dzR2Z/5B1nwCQ== From: Jia-Ju Bai To: tim@cyberelk.net Cc: linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] block: paride: on26: Replace mdelay with msleep in on26_test_port Date: Fri, 26 Jan 2018 23:42:25 +0800 Message-Id: <1516981345-8202-1-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 After checking all possible call chains to on26_test_port() here, my tool finds that this function is never called in atomic context, namely never in an interrupt handler or holding a spinlock. And on26_test_port() is only called by pi_probe_unit() that calls wait_event() through pi_claim(), so it indicates that on26_test_port() can call functions that can sleep. Thus mdelay can be replaced with msleep to avoid busy wait. This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai --- drivers/block/paride/on26.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/paride/on26.c b/drivers/block/paride/on26.c index 95ba256..3240d6f 100644 --- a/drivers/block/paride/on26.c +++ b/drivers/block/paride/on26.c @@ -163,7 +163,7 @@ static int on26_test_port( PIA *pi) /* hard reset */ on26_write_regr(pi,0,6,0xb0); y = on26_read_regr(pi,0,7); if (!((x&0x80)||(y&0x80))) break; - mdelay(100); + msleep(100); } if (i == RESET_WAIT) -- 1.7.9.5