Date: Sun, 23 Oct 2005 19:57:00 -0700 From: Daniel Rudy <dr2867@pacbell.net> To: freebsd-hackers@freebsd.org Subject: devinfo(3) problem... Message-ID: <435C4D7C.7080504@pacbell.net>
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Consider the following code fragment:
(segment 2)
Calling code section:
/* get devinfo root nexus */
printf("root ptr: %p\n", root);
result = usb_devinfo_root(&root);
printf("root ptr: %p\n", root);
if (result < 0)
{
usb_devinfo_close();
return(-1);
}
/* internal: get devinfo root nexus */
int usb_devinfo_root(struct devinfo_dev **root)
{
printf("root: %p\n", *root);
*root = devinfo_handle_to_device(DEVINFO_ROOT_DEVICE);
printf("root: %p\n", *root); <---- second call printf
if (*root == NULL)
{
if (usb_param_use_error == TRUE) error("usb.c: usb_devinfo_root:
root device not found", errno);
if (usb_param_errors_fatal == TRUE) exit(2);
return(-1);
}
return(0);
}
The problem is that devinfo_handle_to_device always returns a null
pointer here. Why? The next code segment, devinfo_handle_to_device
returns a proper address.
(segment 1)
/* get devinfo root nexus */
root = devinfo_handle_to_device(DEVINFO_ROOT_DEVICE);
if (root == NULL)
{
devinfo_free();
return(-1);
}
output:
usb_param_devmode: 255
usb_param_devtype: 255
usb_param_mode_pref: 0
ioctl result: -1
devinfo result: 0
found_ioctl: 0
found_devinfo: 1 <---- first call
devinfo device name: umass0
usb_devinfo_open result: 0
root ptr: 0x2815769c
root: 0x2815769c
root: 0x0 <---- second call
usb.c: usb_devinfo_root: root device not found: No such file or directory
root ptr: 0x0
Fatal: Unable to get device information
Now I have made sure that I have called devinfo_free() during the first
call before calling devinfo_init() a second time. I tried calling this
code branch on the first time, and it executes properly, so why does it
fail on the second call?
--
Daniel Rudy
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