On Wed, 10 Aug 2011, Mauro Carvalho Chehab wrote: > Em 10-08-2011 15:33, Theodore Kilgore escreveu: > > > Hans seems to have argued cogently for doing all of this in the kernel and > > for abandoning the usbfs-based drivers for these particular drivers for > > dual-mode cameras and, I would conjecture, for drivers for dual-mode > > hardware in general. Therefore, I anticipate that he won't like that very > > much. > > > > My position: > > > > I do not have preconceptions about how the problem gets handled, and at > > this point I remain agnostic and believe that all approaches ought to be > > carefully analysed. I can imagine, abstractly, that things like this > > could be handled by > > > > -- moving all basic functionality to the kernel, and fixing the > > relevant libgphoto2 drivers to look to the kernel instead of to libusb. > > (What Hans argues for, and I am not opposed if his arguments convince > > other concerned parties) > > Not looking on the amount of work to be done, I think that this would > give better results, IMO. Okay. I would guess that I am one of the guys who gets to do the work, though. > > > -- doing some kind of patch job to make current arrangement somehow to > > work better (this seems to be the position of Adam Baker; I do share > > the skepticism Hans has expressed about how well this could all be > > pasted together) > > Adam Baker's proposal of a locking between usbfs and the kernel driver seems > to be interesting, but, as he pointed, there are some side effects to consider, > like suspend/resume, PM, etc. > > > -- doing something like the previous, but also figuring out how to bring > > udev rules into play, which would make it all work better (just tossing > > this one in, for laughs, but who knows someone might like it) > > I don't think this is a good alternative. I was trying to mention all alternatives. I should have also mentioned "leave things the way they are" but that is certainly out the window. > > > -- moving the kernel webcam drivers out of the kernel and doing with these > > cameras _everything_ including webcam function through libusb. I myself do > > not have the imagination to be able to figure out how this could be done > > without a rather humongous amount of work (for example, which streaming > > apps that are currently available would be able to live with this?) but > > unless I misunderstand what he was saying, Greg K-H seems to think that > > this would be the best thing to do. > > I also don't think that this a good alternative. As Hans V. pointed, one of > our long term targets is to create per-sensor I2C drivers that are independent > from the bridges. Also, moving it to userspace would require lots of work > with the duplication of V4L and gspca core into userspace for the devices > that would be moved, and may have some performance impacts. A good argument, though it probably does not affect the devices on my list one way or the other. > > > Which one of these possibile approaches gets adopted is a policy issue > > which I would consider is ultimately way above my pay grade. > > > > My main motivation for bringing up the issue was to get it to the front > > burner so that _something_ gets done. It is a matter which has been left > > alone for too long. Therefore, I am very glad that the matter is being > > addressed. > > > > Let me add to this that I have gotten permission for time off and for a > > expense money which might possibly cover my air fare. I hope to arrive in > > Vancouver by sometime on Monday and intend to attend the mini-summit. I > > suggest that we get all intersted parties together and figure out what is > > the best way to go. > > > > I hope everyone who is actively concerned can meet in Vancouver, and if > > all goes well then on Monday as well as Tuesday. I can hang around for > > another day or two after Tuesday, but I do not expect to register for > > LinuxCon or be involved in it. > > It will be great to have you there for those discussions. My take on this was that it seems to have become important for me to attend, which, frankly, I was not expecting. So thanks for the nice words. > > > When I leave Vancouver I will probably go > > to Seattle and spend a couple of days with my oldest son, the musician, > > before coming home on the next weekend. > > > > Theodore Kilgore > -- 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
