From: Jean-Francois Moine <moinejf@free.fr>
To: "Erik Andrén" <erik.andren@gmail.com>
Cc: James Blanford <jhblanford@gmail.com>, linux-media@vger.kernel.org
Subject: Re: Race in gspca main or missing lock in stv06xx subdriver?
Date: Sat, 3 Oct 2009 09:28:00 +0200 [thread overview]
Message-ID: <20091003092800.27fbafb8@tele> (raw)
In-Reply-To: <62e5edd40910010623w58232a7cnf77a2e0c3679aab3@mail.gmail.com>
On Thu, 1 Oct 2009 15:23:29 +0200
Erik Andrén <erik.andren@gmail.com> wrote:
> 2009/9/15 Jean-Francois Moine <moinejf@free.fr>:
[snip]
> > I think you may have found a big problem, and this one should exist
> > in all drivers!
> >
> > As I understood, you say that the URB completion routine (isoc_irq)
> > may be run many times at the same time.
[snip]
> > Then, to fix this problem, I see only one solution: have a private
> > tasklet to do the video streaming, as this is done for some bulk
> > transfer...
[snip]
> Are you currently working on anything addressing this issue or do we
> need some further discussion?
Hi Erik,
No, I am not working on this problem: I cannot reproduce it (easy test:
have a static variable which is incremented in the irq function -
isoc_irq() in gspca.c - and warn when it is non null at entry).
May you (or anyone) check it?
Then, the simplest solution is not a tasklet, but to use only one URB
(change the '#define DEF_NURBS' to 1 instead of 3 in gspca.c).
Best regards.
--
Ken ar c'hentañ | ** Breizh ha Linux atav! **
Jef | http://moinejf.free.fr/
next prev parent reply other threads:[~2009-10-03 7:27 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-14 15:17 Race in gspca main or missing lock in stv06xx subdriver? James Blanford
2009-09-15 10:41 ` Jean-Francois Moine
2009-10-01 13:23 ` Erik Andrén
2009-10-03 7:28 ` Jean-Francois Moine [this message]
2009-10-04 10:45 ` Erik Andrén
2009-10-04 15:36 ` Hans de Goede
2009-10-04 16:41 ` Jean-Francois Moine
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