From: "Frank Schäfer" <fschaefer.oss@googlemail.com>
To: dheitmueller@kernellabs.com
Cc: linux-media@vger.kernel.org
Subject: Re: [PATCH 00/23] em28xx: add support fur USB bulk transfers
Date: Tue, 23 Oct 2012 22:02:24 +0300 [thread overview]
Message-ID: <5086E9C0.5060701@googlemail.com> (raw)
In-Reply-To: <CAGoCfiw-nL03s=JSc_MVzR0+hQEfHV5i+FMf41EbEME8jw3wQg@mail.gmail.com>
Hi,
Am 21.10.2012 21:13, schrieb Devin Heitmueller:
> Hi Frank,
>
> On Sun, Oct 21, 2012 at 12:52 PM, Frank Schäfer
> <fschaefer.oss@googlemail.com> wrote:
>> This patch series adds support for USB bulk transfers to the em28xx driver.
> This is a welcome change that some users have been asking about for a while.
Yes, I know...
>
>> Patch 1 is a bugfix for the image data processing with non-interlaced devices (webcams)
>> that should be considered for stable (see commit message).
>>
>> Patches 2-21 extend the driver to support USB bulk transfers.
>> USB endpoint mapping had to be extended and is a bit tricky.
>> It might still not be sufficient to handle ALL isoc/bulk endpoints of ALL existing devices,
>> but it should work with the devices we have seen so far and (most important !)
>> preserves backwards compatibility to the current driver behavior.
>> Isoc endpoints/transfers are preffered by default, patch 21 adds a module parameter to change this behavior.
>>
>> The last two patches are follow-up patches not really related to USB tranfers.
>> Patch 22 reduces the code size in em28xx-video by merging the two URB data processing functions
> This is generally good stuff. When I originally added the VBI
> support, I kept the URB handlers separate initially to reduce the risk
> of breaking existing devices, and always assumed that at some point
> the two routines would be merged. You did regression test without VBI
> support enabled though, right?
Yes, but when you take a look at the code, you will see that this patch
nothing really changes for VBI devices.
The problem / regression potential is the non-VBI-devices as they are
now using the VBI-version, too, but they have been tested.
Btw, why didn't you test this function with VBI disabled when you added
it ? ;)
>
>> and patch 23 enables VBI-support for em2840-devices.
> Patch 23 shouldn't be applied unless somebody has an em2840 device to
> test with first. Nobody has complained about this so far, and it's
> better to not support VBI than to possibly break existing support.
Btw, what about em2874 / em2884 / em28174 ?
We should really sort these kind of things out when adding new devices...
>
>> Please note that I could test the changes with an analog non-interlaced non-VBI device only !
>> So further tests with DVB/interlaced/VBI devices are strongly recommended !
> So here's the problem: I don't have the cycles to test this, and all
> the refactoring presents a very real risk that breakage of existing
> support could occur. You've basically got three options if you want
> to see this merged upstream:
>
> 1. Wait for me to eventually do the testing.
> 2. Plead for users to do testing, in particular of the VBI support
> for interlaced devices (which is 99% of devices out there)
> 3. See if Mauro has time to do the testing.
I would say 1 + 2 + 3 ;)
And maybe it's a good chance for the people who were asking for this
feature in the past.
I know there are lots of other people on this list having such a device.
> 4. Spend $30 and buy one of the dozens of em28xx based analog capture
> devices out there and do the validation yourself (a huge percentage of
> the "Video tape capture devices" are em28xx based. For example, when
> I did the original VBI work, I used the following:
>
> KWorld DVD Maker USB 2.0 VS- USB2800 USB 2.0 Interface
> http://www.newegg.com/Product/Product.aspx?Item=N82E16815100112
>
> If you're in the United States, I can mail you a device for testing.
> But given how dirt-cheap they are, buying one yourself might be easier
> (and if the money is really the issue, send me your paypal details
> offline and I'll give you the $30.00).
No, thank you. I already have too many devices which I actually don't need.
I'm doing this as a hobby and at the moment, I'm focussed on getting the
devices I already have working properly (which isn't a small task).
I personally don't need this feature uptsream at the moment.
The device I used for testing supports ISOC as well and the em25xx
webcam I'm currently working on will likely use gspca at the end.
> Thanks for you hard work on this, and it will be great to get this
> stuff into the mainline.
I did what I could do. Now its up to others ;)
Regards,
Frank
> Devin
>
next prev parent reply other threads:[~2012-10-23 20:02 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-21 16:52 [PATCH 00/23] em28xx: add support fur USB bulk transfers Frank Schäfer
2012-10-21 16:52 ` [PATCH 01/23] em28xx: fix wrong data offset for non-interlaced mode in em28xx_copy_video Frank Schäfer
2012-10-21 16:52 ` [PATCH 02/23] em28xx: clarify meaning of field 'progressive' in struct em28xx Frank Schäfer
2012-10-21 16:52 ` [PATCH 03/23] em28xx: rename isoc packet number constants and parameters Frank Schäfer
2012-10-21 16:52 ` [PATCH 04/23] em28xx: rename struct em28xx_usb_isoc_bufs to em28xx_usb_bufs Frank Schäfer
2012-10-21 16:52 ` [PATCH 05/23] em28xx: rename struct em28xx_usb_isoc_ctl to em28xx_usb_ctl Frank Schäfer
2012-10-21 16:52 ` [PATCH 06/23] em28xx: remove obsolete #define EM28XX_URB_TIMEOUT Frank Schäfer
2012-10-21 16:52 ` [PATCH 07/23] em28xx: update description of em28xx_irq_callback Frank Schäfer
2012-10-21 16:52 ` [PATCH 08/23] em28xx: rename function em28xx_uninit_isoc to em28xx_uninit_usb_xfer Frank Schäfer
2012-10-21 16:52 ` [PATCH 09/23] em28xx: create a common function for isoc and bulk URB allocation and setup Frank Schäfer
2012-10-21 16:52 ` [PATCH 10/23] em28xx: create a common function for isoc and bulk USB transfer initialization Frank Schäfer
2012-10-21 16:52 ` Frank Schäfer
2012-10-21 16:52 ` [PATCH 11/23] em28xx: clear USB halt/stall condition in em28xx_init_usb_xfer when using bulk transfers Frank Schäfer
2012-10-21 16:52 ` [PATCH 12/23] em28xx: remove double checks for urb->status == -ENOENT in urb_data_copy functions Frank Schäfer
2012-10-21 16:52 ` [PATCH 13/23] em28xx: rename function em28xx_isoc_copy and extend for USB bulk transfers Frank Schäfer
2012-10-21 16:52 ` [PATCH 14/23] em28xx: rename function em28xx_isoc_copy_vbi " Frank Schäfer
2012-10-21 16:52 ` [PATCH 15/23] em28xx: rename function em28xx_dvb_isoc_copy " Frank Schäfer
2012-10-21 16:52 ` [PATCH 16/23] em28xx: rename usb debugging module parameter and macro Frank Schäfer
2012-10-21 16:52 ` [PATCH 17/23] em28xx: rename some USB parameter fields in struct em28xx to clarify their role Frank Schäfer
2012-10-21 16:52 ` [PATCH 18/23] em28xx: add fields for analog and DVB USB transfer type selection to struct em28xx Frank Schäfer
2012-10-21 16:52 ` [PATCH 19/23] em28xx: set USB alternate settings for analog video bulk transfers properly Frank Schäfer
2012-10-21 16:52 ` [PATCH 20/23] em28xx: improve USB endpoint logic, also use bulk transfers Frank Schäfer
2012-10-21 16:52 ` [PATCH 21/23] em28xx: add module parameter for selection of the preferred USB transfer type Frank Schäfer
2012-10-21 16:52 ` [PATCH 22/23] em28xx: use common urb data copying function for vbi and non-vbi devices Frank Schäfer
2012-10-21 16:52 ` [PATCH 23/23] em28xx: enable VBI-support for em2840 devices Frank Schäfer
2012-10-21 18:13 ` [PATCH 00/23] em28xx: add support fur USB bulk transfers Devin Heitmueller
2012-10-23 19:02 ` Frank Schäfer [this message]
[not found] ` <20121028175752.447c39d5@redhat.com>
2012-10-29 15:33 ` Frank Schäfer
2012-10-29 20:03 ` Mauro Carvalho Chehab
2012-10-29 21:14 ` Frank Schäfer
2012-10-30 3:00 ` Mauro Carvalho Chehab
2012-10-30 4:06 ` Mauro Carvalho Chehab
2012-10-30 13:08 ` Devin Heitmueller
2012-10-30 14:03 ` Mauro Carvalho Chehab
2012-10-30 17:29 ` Frank Schäfer
2012-10-30 17:18 ` Frank Schäfer
2012-11-08 18:03 ` Frank Schäfer
2012-11-09 15:02 ` Mauro Carvalho Chehab
2012-11-09 16:03 ` Frank Schäfer
2012-10-31 1:39 ` Benny Amorsen
2012-10-31 10:57 ` Ezequiel Garcia
2012-10-31 12:03 ` Frank Schäfer
2012-10-31 20:24 ` Benny Amorsen
2012-10-31 20:22 ` Benny Amorsen
2012-10-31 11:50 ` Frank Schäfer
2012-10-31 19:58 ` Benny Amorsen
2012-10-31 20:25 ` Ezequiel Garcia
2012-10-31 22:26 ` Benny Amorsen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5086E9C0.5060701@googlemail.com \
--to=fschaefer.oss@googlemail.com \
--cc=dheitmueller@kernellabs.com \
--cc=linux-media@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.