lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 19 Sep 2014 23:44:26 +0200
From:	Javier Martinez Canillas <>
To:	Joe Perches <>
CC:	Andrew Morton <>,
	Alessandro Zummo <>,
	Doug Anderson <>,
	Krzysztof Kozlowski <>,,,,
Subject: Re: [PATCH v10 5/6] rtc: max77686: Use ffs() to calculate tm_wday

Hello Joe,

On 09/19/2014 09:52 PM, Joe Perches wrote:
> On Fri, 2014-09-19 at 21:27 +0200, Javier Martinez Canillas wrote:
>> On 09/19/2014 04:39 PM, Joe Perches wrote:
>> > On Fri, 2014-09-19 at 12:26 +0200, Javier Martinez Canillas wrote:
>> >> The function max77686_rtc_calculate_wday() is used to
>> >> calculate the day of the week to be filled in struct
>> >> rtc_time but that function only calculates the number
>> >> of bits shifted. So the ffs() function can be used to
>> >> find the first bit set instead of a special function.
>> > 
>> > This isn't the same logic.  Perhaps you want fls.
>> >
>> Right, the removed function has the same logic than fls() - 1 but the value
>> stored in data[RTC_WEEKDAY] is:
>> data[RTC_WEEKDAY] = 1 << tm->tm_wday;
>> so for this particular case, it doesn't matter since ffs() == fls() always.
> I didn't look that far.
> I just wanted to show that the logic wasn't the same.

No worries, thanks a lot for your feedback. Probably it would had been good to
mention that in the commit message.

> Perhaps you can specify that ffs==fls in the changelog.

I won't say I'm thrilled to do a whole re-spin of the series just to change
that ;)

Specially since I already did too many revisions and this series have been
floating around for months but is up to Andrew to decide if is worth it.

Best regards,

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists