Re: [Linux-uvc-devel] [SVN] Added preliminary pan/tilt support for Quickcam Orbit MP

[Laurent P. <lau...@sk...>]

> > > Well another question I use :
> > > int err =0;
> > >     queryctrl->id = control;
> > >     if ((err= ioctl(vd->fd, VIDIOC_QUERYCTRL, queryctrl)) < 0) {
> > > 	printf("ioctl querycontrol error %d \n",err);
> > > to verify the control V4L2_CID_PANTILT_RESET  exist
> > >  for some strange reason the ioctl return -EPERM ?
> >
> > Print errno instead of err. ioctl() returns -1 (== -EPERM) in case of
> > failure. The error code is stored in errno.
>
> errno is set with  EIO

Could you apply this patch and tell me what you get in the kernel log ?

Laurent Pinchart

Index: uvcvideo.c
===================================================================
--- uvcvideo.c  (revision 18)
+++ uvcvideo.c  (working copy)
@@ -1362,8 +1362,8 @@
                        unit << 8 | intfnum, data, size, UVC_CTRL_TIMEOUT);

        if (ret != size) {
-               uvc_printk(KERN_ERR, "Failed to query UVC control %u "
-                       "(unit %u) : %d.\n", cs, unit, ret);
+               uvc_printk(KERN_ERR, "Failed to query (%u) UVC control %u "
+                       "(unit %u) : %d.\n", query, cs, unit, ret);
                return -EIO;
        }