linux-kernel - Re: [PATCH v4] media: Driver for Toshiba et8ek8 5MP sensor

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]

Message-ID: <20161120153153.GD5189@amd>
Date:   Sun, 20 Nov 2016 16:31:54 +0100
From:   Pavel Machek <pavel@....cz>
To:     Sakari Ailus <sakari.ailus@....fi>
Cc:     ivo.g.dimitrov.75@...il.com, sre@...nel.org, pali.rohar@...il.com,
        linux-media@...r.kernel.org, galak@...eaurora.org,
        mchehab@....samsung.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4] media: Driver for Toshiba et8ek8 5MP sensor

Hi!

> > +	/* V4L2_CID_EXPOSURE */
> > +	min = et8ek8_exposure_rows_to_us(sensor, 1);
> > +	max = et8ek8_exposure_rows_to_us(sensor,
> > +				sensor->current_reglist->mode.max_exp);
> 
> Haven't I suggested to use lines instead? I vaguely remember doing so...
> this would remove quite some code from the driver.

Lines ... lines ... no, I don't think I understand how to use lines
here. I guess I could switch units from us to rows here...?

Is it good idea? For userspace, microseconds are really a nice
interface, because ... well, that's what photographers are used to
think about (ISO 400, time 1/100). fcam also uses usec internally.

In the current camera code, I do autogain in small resolution, then
use same parameters (gain, time) at higher resolution. I guess I could
do the same with the non-microseconds interface, but then I'd have to
move the microsecond computation into userspace. And userspace is
not really good place to do that, as it does not know (and should not
have to know!) such low level details.

So... can we keep the interface as it is?

Thanks,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Download attachment "signature.asc" of type "application/pgp-signature" (182 bytes)