diff options
| -rw-r--r-- | libusb/os/windows_usb.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/libusb/os/windows_usb.c b/libusb/os/windows_usb.c index 42b7133..2d1526d 100644 --- a/libusb/os/windows_usb.c +++ b/libusb/os/windows_usb.c @@ -3220,11 +3220,28 @@ static int _hid_get_feature(struct hid_device_priv* dev, HANDLE hid_handle, int usbi_dbg("report ID: 0x%02X", buf[0]); if (HidD_GetFeature(hid_handle, buf, read_size)) { - if (buf[0] != id) { - usbi_dbg("program assertion failed - mismatched report ID (got %02X instead of %02X)", - buf[0], id); + // There is a major bug with HidD_GetFeature where the actual data payload starts + // at buf+0 when report IDs are in use by the device, but buf+1 otherwise. + // To try to work around this bug, we assume that if the id provided is + // nonzero, then report IDs are in use by the device + if (id != 0) { + // Try to compensate for a wrong assumption + if ((buf[read_size-1] != 0) && (buf[0] == 0)) { + usbi_warn(NULL, "program assertion failed - report ID provided but device does not"); + usbi_warn(NULL, "seem to use report IDs. Compensating by shifting payload data"); + memcpy(data, buf+1, read_size); + } else { + memcpy(data, buf, read_size); + } + } else { + if (buf[0] != 0) { + usbi_warn(NULL, "program assertion failed - report ID received (0x%02X) was", buf[0]); + usbi_warn(NULL, "supposed to be zero. Compensating by shifting payload data"); + memcpy(data, buf, read_size); + } else { + memcpy(data, buf+1, read_size); + } } - memcpy(data, buf+1, read_size); r = LIBUSB_COMPLETED; } else { err = GetLastError(); |