From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: Johan Hovold <johan@kernel.org>,
Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: j-keerthy@ti.com, a.zummo@towertech.it,
linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rtc: rtc-omap: Replace mdelay() with msleep() in omap_rtc_power_off()
Date: Tue, 28 Aug 2018 17:06:00 +0800 [thread overview]
Message-ID: <72f42d57-90d1-83d5-3d1d-e82a2250a8ff@gmail.com> (raw)
In-Reply-To: <20180828084940.GA28861@localhost>
On 2018/8/28 16:49, Johan Hovold wrote:
> On Mon, Aug 27, 2018 at 10:55:17PM +0200, Alexandre Belloni wrote:
>> Hi,
>>
>> On 30/07/2018 21:53:14+0800, Jia-Ju Bai wrote:
>>> omap_rtc_power_off() is never called in atomic context.
>>> It calls mdelay() to busily wait, which is not necessary.
>>> mdelay() can be replaced with msleep().
>>>
>>> This is found by a static analysis tool named DCNS written by myself.
>>>
>>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
>>> ---
>>> drivers/rtc/rtc-omap.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
>>> index 39086398833e..ef3d09525d0f 100644
>>> --- a/drivers/rtc/rtc-omap.c
>>> +++ b/drivers/rtc/rtc-omap.c
>>> @@ -476,7 +476,7 @@ static void omap_rtc_power_off(void)
>>> * power off the system. Add a 500 ms margin for external latencies
>>> * (e.g. debounce circuits).
>>> */
>>> - mdelay(2500);
>>> + msleep(2500);
>> I'm not sure about that one because this is a poweroff function so it
>> doesn't really make sense to sleep versus busy waiting (all the drivers
>> in power/reset use mdelay())
> This power-off handler is called with interrupts disabled (as mentioned
> in the function header) and must not sleep.
Thanks for your reply :)
I check the code again, and find that you are right.
Sorry for my incorrect report.
Best wishes,
Jia-Ju Bai
prev parent reply other threads:[~2018-08-28 12:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-30 13:53 [PATCH] rtc: rtc-omap: Replace mdelay() with msleep() in omap_rtc_power_off() Jia-Ju Bai
2018-08-27 20:55 ` Alexandre Belloni
2018-08-28 8:49 ` Johan Hovold
2018-08-28 9:06 ` Jia-Ju Bai [this message]
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