Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-13 Thread Felipe Balbi
Hi, On Fri, Jun 10, 2011 at 05:43:06PM -0500, Theodore Kilgore wrote: there's nothing in the USB spec that says you need different product IDs for different modes of operation. No matter if it's still or webcam configuration, the underlying function is the same: capture images using a set

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-13 Thread Mauro Carvalho Chehab
Em 13-06-2011 06:05, Felipe Balbi escreveu: Hi, On Fri, Jun 10, 2011 at 05:43:06PM -0500, Theodore Kilgore wrote: there's nothing in the USB spec that says you need different product IDs for different modes of operation. No matter if it's still or webcam configuration, the underlying

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-12 Thread Hans de Goede
Hi, On 06/11/2011 06:19 PM, Theodore Kilgore wrote: On Sat, 11 Jun 2011, Hans de Goede wrote: Hi, Given the many comments in this thread, I'm just going reply to this one, and try to also answer any other ones in this mail. As far as the dual mode camera is involved, I agree that that

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-12 Thread Theodore Kilgore
On Sun, 12 Jun 2011, Hans de Goede wrote: Hi, On 06/11/2011 06:19 PM, Theodore Kilgore wrote: On Sat, 11 Jun 2011, Hans de Goede wrote: Hi, Given the many comments in this thread, I'm just going reply to this one, and try to also answer any other ones in this

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-12 Thread Xiaofan Chen
On Mon, Jun 13, 2011 at 5:20 AM, Theodore Kilgore kilg...@banach.math.auburn.edu wrote: On Sun, 12 Jun 2011, Hans de Goede wrote: Actually libusb and libgphoto have been using the rebind orginal driver functionality of the code for quite a while now, Oh? I can see that libusb is doing that,

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-11 Thread Hans de Goede
Hi, Given the many comments in this thread, I'm just going reply to this one, and try to also answer any other ones in this mail. As far as the dual mode camera is involved, I agree that that should be fixed in the existing v4l2 drivers + libgphoto. I think that Felipe's solution to also handle

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-11 Thread Theodore Kilgore
On Sat, 11 Jun 2011, Hans de Goede wrote: Hi, Given the many comments in this thread, I'm just going reply to this one, and try to also answer any other ones in this mail. As far as the dual mode camera is involved, I agree that that should be fixed in the existing v4l2 drivers +

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-11 Thread Alan Stern
On Sat, 11 Jun 2011, Hans de Goede wrote: So what do we need to make this situation better: 1) A usb_driver callback alternative to the disconnect callback, I propose to call this soft_disconnect. This serves 2 purposes a) It will allow the driver to tell the caller that that is

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Felipe Balbi
Hi, On Fri, Jun 10, 2011 at 09:55:13AM +0200, Hans de Goede wrote: Currently this will cause the usb mass storage driver to see a disconnect, and any possible still pending writes are lost ... This is IMHO unacceptable, but currently there is nothing we can do to avoid this. 2) So called

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Hans de Goede
Hi, On 06/10/2011 10:22 AM, Felipe Balbi wrote: Hi, On Fri, Jun 10, 2011 at 09:55:13AM +0200, Hans de Goede wrote: Currently this will cause the usb mass storage driver to see a disconnect, and any possible still pending writes are lost ... This is IMHO unacceptable, but currently there is

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Felipe Balbi
Hi, On Fri, Jun 10, 2011 at 10:36:47AM +0200, Hans de Goede wrote: On Fri, Jun 10, 2011 at 09:55:13AM +0200, Hans de Goede wrote: Currently this will cause the usb mass storage driver to see a disconnect, and any possible still pending writes are lost ... This is IMHO unacceptable, but

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Hans de Goede
Hi, On 06/10/2011 10:42 AM, Felipe Balbi wrote: Hi, On Fri, Jun 10, 2011 at 10:36:47AM +0200, Hans de Goede wrote: On Fri, Jun 10, 2011 at 09:55:13AM +0200, Hans de Goede wrote: snip So what do we need to make this situation better: 1) A usb_driver callback alternative to the disconnect

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Felipe Balbi
Hi, On Fri, Jun 10, 2011 at 02:19:20PM +0200, Hans de Goede wrote: So what do we need to make this situation better: 1) A usb_driver callback alternative to the disconnect callback, I propose to call this soft_disconnect. This serves 2 purposes a) It will allow the driver to tell the

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Alan Stern
On Fri, 10 Jun 2011, Hans de Goede wrote: Hi all, The current API for managing kernel - userspace is a bit rough around the edges, so I would like to discuss extending the API. First of all an example use case scenarios where the current API falls short. 1) Redirection of USB devices

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Mauro Carvalho Chehab
Em 10-06-2011 11:48, Alan Stern escreveu: On Fri, 10 Jun 2011, Hans de Goede wrote: As Felipe has mentioned, this sounds like the sort of problem that can better be solved in userspace. A dual-mode device like the one you describe really is either a still-cam or a webcam, never both at

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Alan Stern
On Fri, 10 Jun 2011, Mauro Carvalho Chehab wrote: Em 10-06-2011 11:48, Alan Stern escreveu: On Fri, 10 Jun 2011, Hans de Goede wrote: As Felipe has mentioned, this sounds like the sort of problem that can better be solved in userspace. A dual-mode device like the one you

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Felipe Balbi
Hi, On Fri, Jun 10, 2011 at 01:16:47PM -0500, Theodore Kilgore wrote: As I have been involved in writing the drivers (both the kernel and the libgphoto2 drivers) for many of the affected cameras, perhaps I should expand on this problem. There are lots of responses to this original message

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Theodore Kilgore
On Fri, 10 Jun 2011, Hans de Goede wrote: Hi all, The current API for managing kernel - userspace is a bit rough around the edges, so I would like to discuss extending the API. [...] 2) So called dual mode cameras are (cheap) stillcams often even without an lcdscreen viewfinder, and

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Alan Stern
On Fri, 10 Jun 2011, Felipe Balbi wrote: I don't see any problems in this situation. If, for that particular product, webcam and still image functionality are mutually exclusive, then that's how the product (and their drivers) have to work. If the linux community decided to put webcam

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Felipe Balbi
Hi, On Fri, Jun 10, 2011 at 05:18:39PM -0400, Alan Stern wrote: 2. Until recently in the history of Linux, there was an irreconcilable conflict. If a kernel driver for the video streaming mode was present and installed, it was not possible to use the camera in stillcam mode at all.

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Theodore Kilgore
On Fri, 10 Jun 2011, Felipe Balbi wrote: Hi, On Fri, Jun 10, 2011 at 01:16:47PM -0500, Theodore Kilgore wrote: As I have been involved in writing the drivers (both the kernel and the libgphoto2 drivers) for many of the affected cameras, perhaps I should expand on this problem. There

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Theodore Kilgore
On Fri, 10 Jun 2011, Alan Stern wrote: On Fri, 10 Jun 2011, Felipe Balbi wrote: I don't see any problems in this situation. If, for that particular product, webcam and still image functionality are mutually exclusive, then that's how the product (and their drivers) have to work.

Re: Improving kernel - userspace (usbfs) usb device hand off

2011-06-10 Thread Xiaofan Chen
On Sat, Jun 11, 2011 at 6:43 AM, Theodore Kilgore kilg...@banach.math.auburn.edu wrote: I do not believe that we have found the optimal solution, yet. The ideal thing would be some kind of hack which allows the kernel to be used when it is needed, and when it is not needed it does not