<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/usb/gadget/uvc_queue.c, branch v3.11</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>usb: gadget: uvc: Implement videobuf2 .wait_prepare and .wait_finish operations</title>
<updated>2013-06-04T20:27:50+00:00</updated>
<author>
<name>Michael Grzeschik</name>
<email>m.grzeschik@pengutronix.de</email>
</author>
<published>2013-02-08T23:54:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a2cc81d315c45cce35c0e50716fbee5dc00e28aa'/>
<id>a2cc81d315c45cce35c0e50716fbee5dc00e28aa</id>
<content type='text'>
Those optional operations are used to release and reacquire the queue
lock when videobuf2 needs to perform operations that sleep for a long
time, such as waiting for a buffer to be complete. Implement them to
avoid blocking qbuf or streamoff calls when a dqbuf is in progress.

Signed-off-by: Michael Grzeschik &lt;m.grzeschik@pengutronix.de&gt;
Signed-off-by: Felipe Balbi &lt;balbi@ti.com&gt;
</content>
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<pre>
Those optional operations are used to release and reacquire the queue
lock when videobuf2 needs to perform operations that sleep for a long
time, such as waiting for a buffer to be complete. Implement them to
avoid blocking qbuf or streamoff calls when a dqbuf is in progress.

Signed-off-by: Michael Grzeschik &lt;m.grzeschik@pengutronix.de&gt;
Signed-off-by: Felipe Balbi &lt;balbi@ti.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: gadget/uvc: Add support for 'get_unmapped_area' for MMUless architectures</title>
<updated>2013-04-02T08:42:49+00:00</updated>
<author>
<name>Bhupesh Sharma</name>
<email>bhupesh.sharma@st.com</email>
</author>
<published>2013-03-28T09:41:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2f1d57069338b14fcf4765ae2c25fc377da45b1f'/>
<id>2f1d57069338b14fcf4765ae2c25fc377da45b1f</id>
<content type='text'>
This patch adds the support for 'get_unmapped_area' in UVC gadget
which is called when the 'mmap' system call is executed on MMUless
architectures.

Signed-off-by: Bhupesh Sharma &lt;bhupesh.sharma@st.com&gt;
Signed-off-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch adds the support for 'get_unmapped_area' in UVC gadget
which is called when the 'mmap' system call is executed on MMUless
architectures.

Signed-off-by: Bhupesh Sharma &lt;bhupesh.sharma@st.com&gt;
Signed-off-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: gadget/uvc: Port UVC webcam gadget to use videobuf2 framework</title>
<updated>2013-04-02T08:42:48+00:00</updated>
<author>
<name>Bhupesh Sharma</name>
<email>bhupesh.sharma@st.com</email>
</author>
<published>2013-03-28T09:41:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d692522577c051058efbe9e3c8aef68a4c36e4f7'/>
<id>d692522577c051058efbe9e3c8aef68a4c36e4f7</id>
<content type='text'>
This patch reworks the videobuffer management logic present in the UVC
webcam gadget and ports it to use the "more apt" videobuf2 framework for
video buffer management.

To support routing video data captured from a real V4L2 video capture
device with a "zero copy" operation on videobuffers (as they pass from
the V4L2 domain to UVC domain via a user-space application), we need to
support USER_PTR IO method at the UVC gadget side.

So the V4L2 capture device driver can still continue to use MMAP IO
method and now the user-space application can just pass a pointer to the
video buffers being dequeued from the V4L2 device side while queueing
them at the UVC gadget end. This ensures that we have a "zero-copy"
design as the videobuffers pass from the V4L2 capture device to the UVC
gadget.

Note that there will still be a need to apply UVC specific payload
headers on top of each UVC payload data, which will still require a copy
operation to be performed in the 'encode' routines of the UVC gadget.

This patch also addresses one issue found out while porting the UVC
gadget to videobuf2 framework:
	- In case the usb requests queued by the gadget get completed
	  with a status of -ESHUTDOWN (disconnected from host),
	  the queue of videobuf2 should be cancelled to ensure that the
	  application space daemon is not left in a state waiting for
	  a vb2 to be successfully absorbed at the USB side.

Signed-off-by: Bhupesh Sharma &lt;bhupesh.sharma@st.com&gt;
Signed-off-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch reworks the videobuffer management logic present in the UVC
webcam gadget and ports it to use the "more apt" videobuf2 framework for
video buffer management.

To support routing video data captured from a real V4L2 video capture
device with a "zero copy" operation on videobuffers (as they pass from
the V4L2 domain to UVC domain via a user-space application), we need to
support USER_PTR IO method at the UVC gadget side.

So the V4L2 capture device driver can still continue to use MMAP IO
method and now the user-space application can just pass a pointer to the
video buffers being dequeued from the V4L2 device side while queueing
them at the UVC gadget end. This ensures that we have a "zero-copy"
design as the videobuffers pass from the V4L2 capture device to the UVC
gadget.

Note that there will still be a need to apply UVC specific payload
headers on top of each UVC payload data, which will still require a copy
operation to be performed in the 'encode' routines of the UVC gadget.

This patch also addresses one issue found out while porting the UVC
gadget to videobuf2 framework:
	- In case the usb requests queued by the gadget get completed
	  with a status of -ESHUTDOWN (disconnected from host),
	  the queue of videobuf2 should be cancelled to ensure that the
	  application space daemon is not left in a state waiting for
	  a vb2 to be successfully absorbed at the USB side.

Signed-off-by: Bhupesh Sharma &lt;bhupesh.sharma@st.com&gt;
Signed-off-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[media] usb: gadget/uvc: Remove non-required locking from 'uvc_queue_next_buffer' routine</title>
<updated>2012-04-10T18:46:02+00:00</updated>
<author>
<name>Bhupesh Sharma</name>
<email>bhupesh.sharma@st.com</email>
</author>
<published>2012-03-22T03:50:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=95faf82bd3ea607f8e1ca78930c49b71078266e6'/>
<id>95faf82bd3ea607f8e1ca78930c49b71078266e6</id>
<content type='text'>
This patch removes the non-required spinlock acquire/release calls on
'queue_irqlock' from 'uvc_queue_next_buffer' routine.

This routine is called from 'video-&gt;encode' function (which translates to either
'uvc_video_encode_bulk' or 'uvc_video_encode_isoc') in 'uvc_video.c'.
As, the 'video-&gt;encode' routines are called with 'queue_irqlock' already held,
so acquiring a 'queue_irqlock' again in 'uvc_queue_next_buffer' routine causes
a spin lock recursion.

Signed-off-by: Bhupesh Sharma &lt;bhupesh.sharma@st.com&gt;
Acked-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch removes the non-required spinlock acquire/release calls on
'queue_irqlock' from 'uvc_queue_next_buffer' routine.

This routine is called from 'video-&gt;encode' function (which translates to either
'uvc_video_encode_bulk' or 'uvc_video_encode_isoc') in 'uvc_video.c'.
As, the 'video-&gt;encode' routines are called with 'queue_irqlock' already held,
so acquiring a 'queue_irqlock' again in 'uvc_queue_next_buffer' routine causes
a spin lock recursion.

Signed-off-by: Bhupesh Sharma &lt;bhupesh.sharma@st.com&gt;
Acked-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb gadget: clean up FSF boilerplate text</title>
<updated>2011-09-09T23:00:09+00:00</updated>
<author>
<name>Klaus Schwarzkopf</name>
<email>schwarzkopf@sensortherm.de</email>
</author>
<published>2011-09-09T14:10:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=28c9fc68ebd32d473a8787d05c74e3f39c6c866b'/>
<id>28c9fc68ebd32d473a8787d05c74e3f39c6c866b</id>
<content type='text'>
remove the following two paragraphs as they are not needed:

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
License for more details.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,59
Temple Place - Suite 330, Boston, MA  02111-1307, USA.

Signed-off-by: Klaus Schwarzkopf &lt;schwarzkopf@sensortherm.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
remove the following two paragraphs as they are not needed:

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
License for more details.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,59
Temple Place - Suite 330, Boston, MA  02111-1307, USA.

Signed-off-by: Klaus Schwarzkopf &lt;schwarzkopf@sensortherm.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>atomic: use &lt;linux/atomic.h&gt;</title>
<updated>2011-07-26T23:49:47+00:00</updated>
<author>
<name>Arun Sharma</name>
<email>asharma@fb.com</email>
</author>
<published>2011-07-26T23:09:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=60063497a95e716c9a689af3be2687d261f115b4'/>
<id>60063497a95e716c9a689af3be2687d261f115b4</id>
<content type='text'>
This allows us to move duplicated code in &lt;asm/atomic.h&gt;
(atomic_inc_not_zero() for now) to &lt;linux/atomic.h&gt;

Signed-off-by: Arun Sharma &lt;asharma@fb.com&gt;
Reviewed-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Acked-by: Mike Frysinger &lt;vapier@gentoo.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This allows us to move duplicated code in &lt;asm/atomic.h&gt;
(atomic_inc_not_zero() for now) to &lt;linux/atomic.h&gt;

Signed-off-by: Arun Sharma &lt;asharma@fb.com&gt;
Reviewed-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Acked-by: Mike Frysinger &lt;vapier@gentoo.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>V4L/DVB: uvc: Fix multiple symbols definitions with UVC gadget and host drivers</title>
<updated>2010-07-11T20:45:10+00:00</updated>
<author>
<name>Laurent Pinchart</name>
<email>laurent.pinchart@ideasonboard.com</email>
</author>
<published>2010-07-10T19:13:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5d9955f8a978c1992a0f9966d22c43471214d43b'/>
<id>5d9955f8a978c1992a0f9966d22c43471214d43b</id>
<content type='text'>
The UVC gadget driver borrowed code from the UVC host driver without
changing the symbol names. This results in a namespace clash with
multiple definitions of several symbols when compiling both drivers in
the kernel.

Make all generic UVC functions and variables static in the UVC gadget
driver, as the symbols are not referenced outside of the gadget driver.
Rename the uvc_trace_param global variable to uvc_gadget_trace_param.

Signed-off-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The UVC gadget driver borrowed code from the UVC host driver without
changing the symbol names. This results in a namespace clash with
multiple definitions of several symbols when compiling both drivers in
the kernel.

Make all generic UVC functions and variables static in the UVC gadget
driver, as the symbols are not referenced outside of the gadget driver.
Rename the uvc_trace_param global variable to uvc_gadget_trace_param.

Signed-off-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB gadget: video class function driver</title>
<updated>2010-05-20T20:21:41+00:00</updated>
<author>
<name>Laurent Pinchart</name>
<email>laurent.pinchart@ideasonboard.com</email>
</author>
<published>2010-05-02T18:57:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cdda479f15cd13fa50a913ca85129c0437cc7b91'/>
<id>cdda479f15cd13fa50a913ca85129c0437cc7b91</id>
<content type='text'>
This USB video class function driver implements a video capture device from the
host's point of view. It creates a V4L2 output device on the gadget's side to
transfer data from a userspace application over USB.

The UVC-specific descriptors are passed by the gadget driver to the UVC
function driver, making them completely configurable without any modification
to the function's driver code.

Signed-off-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This USB video class function driver implements a video capture device from the
host's point of view. It creates a V4L2 output device on the gadget's side to
transfer data from a userspace application over USB.

The UVC-specific descriptors are passed by the gadget driver to the UVC
function driver, making them completely configurable without any modification
to the function's driver code.

Signed-off-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
</feed>
