usb-linux: introduce a usb_linux_alt_setting function

The next patch in this series introduces multiple ways to get the
alt setting dependent upon usb_fs_type, it is cleaner to put this
into its own function.

Note that this patch also changes the assumed alt setting in case
of an error getting the alt setting to be 0 (a sane default) rather
then the interface numberwhich makes no sense.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Hans de Goede 2010-11-24 12:50:00 +01:00 committed by Gerd Hoffmann
parent d2d979c628
commit ed3a328db9

View File

@ -823,13 +823,35 @@ usbdevfs:
return configuration;
}
static uint8_t usb_linux_get_alt_setting(USBHostDevice *s,
uint8_t configuration, uint8_t interface)
{
uint8_t alt_setting;
struct usb_ctrltransfer ct;
int ret;
ct.bRequestType = USB_DIR_IN | USB_RECIP_INTERFACE;
ct.bRequest = USB_REQ_GET_INTERFACE;
ct.wValue = 0;
ct.wIndex = interface;
ct.wLength = 1;
ct.data = &alt_setting;
ct.timeout = 50;
ret = ioctl(s->fd, USBDEVFS_CONTROL, &ct);
if (ret < 0) {
/* Assume alt 0 on error */
return 0;
}
return alt_setting;
}
/* returns 1 on problem encountered or 0 for success */
static int usb_linux_update_endp_table(USBHostDevice *s)
{
uint8_t *descriptors;
uint8_t devep, type, configuration, alt_interface;
struct usb_ctrltransfer ct;
int interface, ret, length, i;
int interface, length, i;
i = usb_linux_get_configuration(s);
if (i < 0)
@ -858,19 +880,7 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
}
interface = descriptors[i + 2];
ct.bRequestType = USB_DIR_IN | USB_RECIP_INTERFACE;
ct.bRequest = USB_REQ_GET_INTERFACE;
ct.wValue = 0;
ct.wIndex = interface;
ct.wLength = 1;
ct.data = &alt_interface;
ct.timeout = 50;
ret = ioctl(s->fd, USBDEVFS_CONTROL, &ct);
if (ret < 0) {
alt_interface = interface;
}
alt_interface = usb_linux_get_alt_setting(s, configuration, interface);
/* the current interface descriptor is the active interface
* and has endpoints */