From: Gerd Knorr <kraxel@bytesex.org>
To: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: bttv hang problem on 2.6.8
Date: Mon, 25 Oct 2004 17:18:41 +0200 [thread overview]
Message-ID: <20041025151841.GA10042@bytesex> (raw)
In-Reply-To: <20041025150349.GA22915@xi.wantstofly.org>
On Mon, Oct 25, 2004 at 05:03:49PM +0200, Lennert Buytenhek wrote:
> (please CC on replies, I'm not on the list)
>
> Hi,
>
> When there is a background thread doing VIDIOCSYNC in a loop, issuing
> VIDIOCSPICT in the current thread on the same file descriptor causes
> it to go into uninterruptable sleep and hang. This is on kernel 2.6.8
> using the bttv driver, and appears easily reproducible.
Don't do that. bttv serializes ioctls with a lock. Well, not all of
them, but the ones which change the state of the filehandle, and both
VIDIOCSYNC + VIDIOCSPICT fall into that group. You simply can't run
them in parallel on the same filehandle.
Gerd
--
#define printk(args...) fprintf(stderr, ## args)
next prev parent reply other threads:[~2004-10-25 19:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-25 15:03 bttv hang problem on 2.6.8 Lennert Buytenhek
2004-10-25 15:18 ` Gerd Knorr [this message]
2004-10-25 16:01 ` Lennert Buytenhek
2004-10-25 20:53 ` Gerd Knorr
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