@@ -822,13 +822,35 @@ 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)
@@ -857,19 +879,7 @@ 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 */
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> --- usb-linux.c | 40 +++++++++++++++++++++++++--------------- 1 files changed, 25 insertions(+), 15 deletions(-)