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@xxxxxxxxxxxxxx> 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 > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
