I seem to be having some trouble in carrying out these instructions: On Thu, 19 Aug 2004, Alan Stern wrote:
> On Wed, 18 Aug 2004, Theodore Kilgore wrote: > > > Hmmm... This could be related to hotplugging. That is, there may be a > hotplug program interfering with the camera. You could try turning off > hotplug support. > I have 1. made /ect/rc.d/rc.hotplug to be non-executable, and 2. booted with parameter "nohotplug" as in Lilo: linux267 nohotplug 3. temporarily removed the files usb.usermap and usbcam (called by libgphoto2 so that a user can access a camera) from /etc/hotplug and/or from /etc/hotpolug/usb. The result is, that no modules related to USB get loaded, and I have to do it by hand. And I have to mount usbfs by hand. And I must be root to access a camera through libgphoto2. Well, OK, no big thing if it finds a problem. But then I get (in spite of these measures and afterwards, on doing things by hand) messages that look like Aug 19 15:48:36 khayyam kernel: usb usb1: default language 0x0409 Aug 19 15:48:36 khayyam kernel: usb usb1: hotplug Aug 19 15:48:36 khayyam kernel: usb usb1: adding 1-0:1.0 (config #1, interface 0 ) Aug 19 15:48:36 khayyam kernel: usb 1-0:1.0: hotplug Aug 19 15:48:36 khayyam kernel: hub 1-0:1.0: usb_probe_interface Aug 19 15:48:36 khayyam kernel: hub 1-0:1.0: usb_probe_interface - got id Aug 19 15:48:36 khayyam kernel: hub 1-0:1.0: standalone hub when I install the modules by hand. So it apperars to me that hotplugging is practically impossible to kill. > Also, you could try loading the usbcore module with the usb_snoop=y > parameter. That way if any other program is communicating with the camera > you'd be able to tell. Unfortunately, the result of modprobe usbcore usbsnoop=y is a line in /var/log/syslog which reads Aug 19 15:30:54 khayyam kernel: usbcore: Unknown parameter `usb_snoop' and meanwhile the error messages I do get are pretty much similar to those I got yesterday. And, oh yes, I forgot to ask. Just in case that this mysterious usb_snoop=y can somehow be made to work, then where will I look for the extra debugging output which it is supposed to provide? Also, another question (not implying that your theories about hotplugging are necessarily incorrect, or anything; I do not much like hotplugging but do not see a way around the need for it): Why do I have problems only with this camera and not with others, not even with other cameras suported by the same libgphoto2/camlibs/sq905 driver? My conjecture would be that if I am having problems with hotplugging, then that would show up for all devices of a given class, or at least for all devices which are similar hardware and are supported by the same software. But what is happening (some of the time but not on every possible occasion) is this: (excerpt from gphoto2 -P --debug log output follows, in which one is supposed to be in the process of downloading a photo, in blocks of 0x8000 bytes at a time, until one gets done; current comments added in parentheses) 1.907236 gphoto2-port(2): Writing message (request=0xc value=0x3 index=0x8000 si ze=1=0x1)... 1.907270 gphoto2-port(3): Hexdump of 1 = 0x1 bytes follows: 0000 00 - . (This was the command to the camera, to be prepared to accept a request for 0x8000 bytes of data) 1.908070 gphoto2-port(2): Reading 32768=0x8000 bytes from port... (now 0x8000 bytes of data are supposed to be downloaded, and would actually appear here in the log file if it were really happening) 2.026479 gphoto2-port(2): Writing message (request=0xc value=0x3 index=0x8000 si z (command to the camera, to be prepared to download next block of data) And, to recapitulate, on my other box things work very well for this same camera, using the same code. And also all other cameras in my possession which use the same driver (four of them, or so) will work on both machines, just fine. Well, I guess I said too many things at once in one message. Bottom line is, I suppose, have we really succeeded in turning off hotplugging, or not? If so I guess it is not hotplugging. But the debug messages make me unsure of that. Also, just how do I turn on usb_snoop=y ? Theodore Kilgore ------------------------------------------------------- SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
