Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver

Em Sáb, 2007-06-02 às 11:00 +0200, Thierry Merle escreveu:
> 
> Mauro Carvalho Chehab a écrit :
> >>> This seems to be an interesting approach.
> >>>
> >>>   
> >>>       
> >> Interesting but impossible to do for ioctl calls.
> >> When the application does a ioctl(fd_of_mnt_video0,VIDIOC_G_FMT,&arg) 
> >> for example, there is no way for the userspace helper to catch this ioctl.
> >> The application could only open/read from the userspace helper's file 
> >> /mnt/video0.
> >> ioctl would still have to be done on the kernel device driver.
> >> I thought also about a /proc interface for decompression algorithms (a 
> >> helper would listen on a /proc file and write on another /proc file) but 
> >> /proc is not designed for that kind of thing.
> >> A separate library seems to be the simplest solution.
> >>     
> >
> > There are some ways for this to work. For example, you may create a
> > helper device for the daemon driver to bind, even requiring it to have
> > root permission.
> >
> >   
> Right, but I am afraid that complex userspace/kernelspace context 
> changes breaks performance.
Yes, there's a risk.

> Nevertheless, I will start to specify the framework.
> The helper daemon would link to the v4l2-apps/lib.

Ok, thanks!
-- 
Cheers,
Mauro

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

---

• Follow-Ups:
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Jiri Slaby <[email protected]>

• References:
  • [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Jiri Slaby <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Mauro Carvalho Chehab <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: "Markus Rechberger" <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Mauro Carvalho Chehab <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: "Markus Rechberger" <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Mauro Carvalho Chehab <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Thierry Merle <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Thierry Merle <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Mauro Carvalho Chehab <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Thierry Merle <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Mauro Carvalho Chehab <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Thierry Merle <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Mauro Carvalho Chehab <[email protected]>
  • Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
    • From: Thierry Merle <[email protected]>

• Prev by Date: Re: __get_free_pages: can GFP_DMA omit GFP_KERNEL and GFP_ATOMIC?
• Next by Date: Re: lid switch hangs notebook
• Previous by thread: Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
• Next by thread: Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver
• Index(es):
  • Date
  • Thread

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]