diff options
| -rw-r--r-- | usb-linux.c | 40 |
1 files changed, 25 insertions, 15 deletions
diff --git a/usb-linux.c b/usb-linux.c index 1f33c2c230..353e1b1232 100644 --- a/usb-linux.c +++ b/usb-linux.c @@ -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 */ |