diff options
| -rw-r--r-- | usb-linux.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/usb-linux.c b/usb-linux.c index 4d22c9cc9d..1a2deb35c9 100644 --- a/usb-linux.c +++ b/usb-linux.c @@ -1088,6 +1088,42 @@ static int usb_linux_update_endp_table(USBHostDevice *s) return 0; } +/* + * Check if we can safely redirect a usb2 device to a usb1 virtual controller, + * this function assumes this is safe, if: + * 1) There are no isoc endpoints + * 2) There are no interrupt endpoints with a max_packet_size > 64 + * Note bulk endpoints with a max_packet_size > 64 in theory also are not + * usb1 compatible, but in practice this seems to work fine. + */ +static int usb_linux_full_speed_compat(USBHostDevice *dev) +{ + int i, packet_size; + + /* + * usb_linux_update_endp_table only registers info about ep in the current + * interface altsettings, so we need to parse the descriptors again. + */ + for (i = 0; (i + 5) < dev->descr_len; i += dev->descr[i]) { + if (dev->descr[i + 1] == USB_DT_ENDPOINT) { + switch (dev->descr[i + 3] & 0x3) { + case 0x00: /* CONTROL */ + break; + case 0x01: /* ISO */ + return 0; + case 0x02: /* BULK */ + break; + case 0x03: /* INTERRUPT */ + packet_size = dev->descr[i + 4] + (dev->descr[i + 5] << 8); + if (packet_size > 64) + return 0; + break; + } + } + } + return 1; +} + static int usb_host_open(USBHostDevice *dev, int bus_num, int addr, char *port, const char *prod_name, int speed) { @@ -1168,6 +1204,9 @@ static int usb_host_open(USBHostDevice *dev, int bus_num, } dev->dev.speed = speed; dev->dev.speedmask = (1 << speed); + if (dev->dev.speed == USB_SPEED_HIGH && usb_linux_full_speed_compat(dev)) { + dev->dev.speedmask |= USB_SPEED_MASK_FULL; + } printf("husb: grabbed usb device %d.%d\n", bus_num, addr); |