linux-kernel - Re: [PATCH] Input: silead: use msleep() for long delays

lists.openwall.net		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 linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20170112185002.GA26272@osadl.at>
Date:   Thu, 12 Jan 2017 18:50:02 +0000
From:   Nicholas Mc Guire <der.herr@...r.at>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:     Hans de Goede <hdegoede@...hat.com>,
        Nicholas Mc Guire <hofrat@...dl.org>,
        Henrik Rydberg <rydberg@...math.org>,
        Rob Herring <robh@...nel.org>,
        Daniel Jansen <djaniboe@...il.com>,
        Dan Carpenter <dan.carpenter@...cle.com>,
        Robert Dolca <robert.dolca@...el.com>,
        "linux-input@...r.kernel.org" <linux-input@...r.kernel.org>,
        lkml <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] Input: silead: use msleep() for long delays

On Thu, Jan 12, 2017 at 10:10:44AM -0800, Dmitry Torokhov wrote:
> On Thu, Jan 12, 2017 at 9:46 AM, Hans de Goede <hdegoede@...hat.com> wrote:
> > Hi,
> >
> > On 01/12/2017 05:21 PM, Nicholas Mc Guire wrote:
> >>
> >> the delays here are in the 10 to 20ms range so msleep() will do - no
> >> need to burden the highres timer subsystem.
> >>
> >> Signed-off-by: Nicholas Mc Guire <hofrat@...dl.org>
> >> ---
> >>
> >> Problem found by coccinelle script
> >>
> >> While msleep(10) has a worst case uncertainty of 10ms (on HZ=100 systems)
> >> this seems ok here as the delays are not called frequently (init and
> >> reset functions)
> >
> >
> > By the same logic, this is not much of a burden on the high-res timer
> > subsys though.
> >
> >> and the uncertainty of 10ms fits the permitted range of
> >> the original usleep_ranges().
> >
> >
> > Either way this patch is fine with me.
> 
> I'd rather not because next will come a checkpatch warrior and I will
> have to convince them why msleep is OK here. And another one, and
> another one... :(
>
there is no checkpatch warning here - checkpatch only throws warnings
of range < 20ms if hardcoded but this is in a #define so its fine with
respect to checkpatch.

But if there are concerns with this - thats fine - its most likely not
critical - the goal is to have a consistent usage of highres timers - 
including limiting there use to the cases where its really needed.

thx!
hofrat