From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x224C77kKi7oN3aNiQFEWotT47MWhij19FU0bFtUD5PJYLOAzOQL6C0iigoVUSKP8nX/I0rsD ARC-Seal: i=1; a=rsa-sha256; t=1518177513; cv=none; d=google.com; s=arc-20160816; b=eA4Xfse6mgKp3Olm1RLcRTTvr5jNBGFRLTSGNt1skvKbZKn/1Rm/h0FOg/pY/vR8j4 Rp/9JCWi3n6Gu3HS4e6TykLZuDw68tlZ+fLAUkGBN+1AjeTaK/J66prYG34kFHJsVcRJ s22wEddgB8x0K1fJ/xztsW31kJ0Y8ZEYcginjAnqywoQ/aUfMbmPdx99WeCj2RsUFXQ/ VECmpksEAyeSTbcIRu5M2BFG1vLcQWIvi/xGje/bgPI0jOWLqcq9PdwvIwOHBxzDer04 6BgAkmciu2UpRbkM39JutfDYX6OAsuwi0oq8KlAt2hT/uqY6ryAqMSbSPCOk5c34nXY/ 1n2w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:arc-authentication-results; bh=QURsZJ80iLdp2Dzjnpmuia7p6hDNm/oAeQDauKnFSho=; b=io+Ob04c33A/8avh8xumAm0XepReBPxugbludSErrgPmlv13UQ29NnKrA/voDGmIqH 5o1pVDw9ga7aAJKsWpqJb+C57zkOmBdth6YmRS7s3G0/CZWBJNFL/X/DD/MMFSIB3xHK RqTDdkU94QUOo2PUg9Pvfu/RU19hMBEKDjH10qhDJWOoxtCvhCSZzwnW1fE3j/3P96St 4N+t+ycVM/bZRItXQZWeHwZRi9wB212lHsoo89t4ei/uOxH6BzTuBjJDUVP5qG/UScoM vFCKsELeJt7HAsTp+Jp8i8eeAzp2RwiInSivDc2YJx/Bqd7DdDBhA4F9pBTMKP9HY1q1 Q+fg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of rjw@rjwysocki.net designates 79.96.170.134 as permitted sender) smtp.mailfrom=rjw@rjwysocki.net Authentication-Results: mx.google.com; spf=pass (google.com: domain of rjw@rjwysocki.net designates 79.96.170.134 as permitted sender) smtp.mailfrom=rjw@rjwysocki.net From: "Rafael J. Wysocki" To: Jia-Ju Bai , khilman@kernel.org, ulf.hansson@linaro.org Cc: len.brown@intel.com, pavel@ucw.cz, gregkh@linuxfoundation.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] base: power: domain: Replace mdelay with msleep Date: Fri, 09 Feb 2018 12:56:50 +0100 Message-ID: <66016771.HTTzQvm2zL@aspire.rjw.lan> In-Reply-To: <1516955899-31810-1-git-send-email-baijiaju1990@gmail.com> References: <1516955899-31810-1-git-send-email-baijiaju1990@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590643262439305991?= X-GMAIL-MSGID: =?utf-8?q?1591924504668787789?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Friday, January 26, 2018 9:38:19 AM CET Jia-Ju Bai wrote: > After checking all possible call chains to genpd_dev_pm_detach() and > genpd_dev_pm_attach() here, > my tool finds that these functions are never called in atomic context, > namely never in an interrupt handler or holding a spinlock. > 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/base/power/domain.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 0c80bea..f84ac72 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -2144,7 +2144,7 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off) > if (ret != -EAGAIN) > break; > > - mdelay(i); > + msleep(i); > cond_resched(); > } > > @@ -2231,7 +2231,7 @@ int genpd_dev_pm_attach(struct device *dev) > if (ret != -EAGAIN) > break; > > - mdelay(i); > + msleep(i); > cond_resched(); > } > mutex_unlock(&gpd_list_lock); > Ulf, Kevin, any concerns or objections?