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Diffstat (limited to 'hw/usb/host-libusb.c')
-rw-r--r--hw/usb/host-libusb.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
index 7dde3d1206..354713a77d 100644
--- a/hw/usb/host-libusb.c
+++ b/hw/usb/host-libusb.c
@@ -836,7 +836,7 @@ static void usb_host_ep_update(USBHostDevice *s)
struct libusb_ss_endpoint_companion_descriptor *endp_ss_comp;
#endif
uint8_t devep, type;
- int pid, ep;
+ int pid, ep, alt;
int rc, i, e;
usb_ep_reset(udev);
@@ -848,8 +848,20 @@ static void usb_host_ep_update(USBHostDevice *s)
conf->bConfigurationValue, true);
for (i = 0; i < conf->bNumInterfaces; i++) {
- assert(udev->altsetting[i] < conf->interface[i].num_altsetting);
- intf = &conf->interface[i].altsetting[udev->altsetting[i]];
+ /*
+ * The udev->altsetting array indexes alternate settings
+ * by the interface number. Get the 0th alternate setting
+ * first so that we can grab the interface number, and
+ * then correct the alternate setting value if necessary.
+ */
+ intf = &conf->interface[i].altsetting[0];
+ alt = udev->altsetting[intf->bInterfaceNumber];
+
+ if (alt != 0) {
+ assert(alt < conf->interface[i].num_altsetting);
+ intf = &conf->interface[i].altsetting[alt];
+ }
+
trace_usb_host_parse_interface(s->bus_num, s->addr,
intf->bInterfaceNumber,
intf->bAlternateSetting, true);