linux-kernel - Re: [PATCH v5 3/4] iio: trigger: Introduce IIO hrtimer based trigger

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

Date:	Wed, 6 May 2015 20:37:25 +0300
From:	Daniel Baluta <daniel.baluta@...el.com>
To:	Jonathan Cameron <jic23@...nel.org>
Cc:	Daniel Baluta <daniel.baluta@...el.com>,
	Lars-Peter Clausen <lars@...afoo.de>,
	Joel Becker <jlbec@...lplan.org>,
	Hartmut Knaack <knaack.h@....de>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
	"octavian.purdila@...el.com" <octavian.purdila@...el.com>,
	Paul Bolle <pebolle@...cali.nl>, patrick.porlan@...el.com,
	adriana.reus@...el.com, constantin.musca@...el.com,
	marten@...uitiveaerial.com
Subject: Re: [PATCH v5 3/4] iio: trigger: Introduce IIO hrtimer based trigger

On Wed, May 6, 2015 at 8:16 PM, Jonathan Cameron <jic23@...nel.org> wrote:
> On 06/05/15 17:25, Daniel Baluta wrote:
>>
>>
>> On 05/05/2015 04:51 PM, Jonathan Cameron wrote:
>>>
>>>
>>> On 4 May 2015 20:54:08 GMT+01:00, Lars-Peter Clausen <lars@...afoo.de> wrote:
>>>> On 05/04/2015 12:50 PM, Daniel Baluta wrote:
>>>> [...]
>>>>> +IIO_HRTIMER_INFO_ATTR(sampling_frequency, S_IRUGO | S_IWUSR,
>>>>> +              iio_hrtimer_info_show_sampling_frequency,
>>>>> +              iio_hrtimer_info_store_sampling_frequency);
>>>>
>>>> I wonder if the sampling frequency should be configurable the regular
>>>> IIO
>>>> API, just like any other IIO device. But things like min/max sampling
>>>> frequency should be configured in configfs.
>>> Would have to be in the trigger dir rather than device... Makes sense to put it there.
>>> Limits on it here seem like a sensible idea.
>>
>> But then each trigger will have sampling_frequency right? This is not what we want.
> I'm confused now.  Why not?  Each hrtimer trigger created in configfs should have
> it's own sampling frequency should it not?

I was referring to triggers in general, not just hrtimer triggers.

But I see now that we can set trig->dev.groups to point to our
specific attributes. This
should work.

Anyhow, I'm not convinced that sampling_frequency should be configured
from sysfs.
We create the trigger from configfs:

$ mkdir /config/triggers/hrtimer-instance0

Then, likely we have to do something like this:

$ echo 100 > /sys/bus/iio/trigger7/sampling_frequency

How is the user application going to know which is the exact directory
for hrtimer-instance0 ?

Daniel.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/