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From: Matthieu CASTET <matthieu.castet@parrot.com>
To: Magnus Damm <magnus.damm@gmail.com>
Cc: video4linux-list@redhat.com,
	Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Subject: Re: soc-camera : sh_mobile_ceu_camera race on free_buffer ?
Date: Mon, 19 Jan 2009 15:02:26 +0100	[thread overview]
Message-ID: <497487F2.7070400@parrot.com> (raw)

Hi,

I am writing a soc camera driver, and I use sh_mobile_ceu_camera as an
example.

But I don't understand how buffer are handled when the application is
doing a streamoff :

streamoff will call videobuf_streamoff and then videobuf_queue_cancel.
videobuf_queue_cancel will call free_buffer.

But we didn't do stop_capture, so as far I understand the controller is
still writing data in memory. What prevent us to free the buffer we are
writing.


Why doesn't we do a stop_capture before videobuf_streamoff ?

I saw that pxa_camera use videobuf_waiton, before freeing the buffer.
That seem more safe, but that mean we need to wait that controller
finish to write all the pending buffer.


Matthieu

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             reply	other threads:[~2009-01-19 14:03 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-19 14:02 Matthieu CASTET [this message]
2009-01-20  4:46 ` soc-camera : sh_mobile_ceu_camera race on free_buffer ? Magnus Damm
2009-01-20  9:27   ` Matthieu CASTET
2009-02-13 10:14     ` Magnus Damm
2009-02-16  1:07       ` morimoto.kuninori
2009-02-18 18:51         ` Guennadi Liakhovetski
2009-02-19  1:01           ` morimoto.kuninori
2009-02-19  7:29             ` Guennadi Liakhovetski
2009-02-19  8:07               ` morimoto.kuninori
2009-02-19  8:33                 ` Guennadi Liakhovetski
2009-02-19  9:30                   ` morimoto.kuninori
2009-02-19  9:51                     ` Guennadi Liakhovetski
2009-02-19 23:56                       ` morimoto.kuninori
2009-02-18 18:56       ` Guennadi Liakhovetski

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