From: Foster Snowhill forst@pen.gy
[ Upstream commit 67927a1b255d883881be9467508e0af9a5e0be9d ]
Apart from the standard "configurations", "interfaces" and "alternate interface settings" in USB, iOS devices also have a notion of "modes". In different modes, the device exposes a different set of available configurations.
Depending on the iOS version, and depending on the current mode, the length and contents of the carrier state control message differs:
* 1 byte (seen on iOS 4.2.1, 8.4): * 03: carrier off (mode 0) * 04: carrier on (mode 0) * 3 bytes (seen on iOS 10.3.4, 15.7.6): * 03 03 03: carrier off (mode 0) * 04 04 03: carrier on (mode 0) * 4 bytes (seen on iOS 16.5, 17.6): * 03 03 03 00: carrier off (mode 0) * 04 03 03 00: carrier off (mode 1) * 06 03 03 00: carrier off (mode 4) * 04 04 03 04: carrier on (mode 0 and 1) * 06 04 03 04: carrier on (mode 4)
Before this change, the driver always used the first byte of the response to determine carrier state.
From this larger sample, the first byte seems to indicate the number of available USB configurations in the current mode (with the exception of the default mode 0), and in some cases (namely mode 1 and 4) does not correlate with the carrier state.
Previous logic erroneously counted `04 03 03 00` as "carrier on" and `06 04 03 04` as "carrier off" on iOS versions that support mode 1 and mode 4 respectively.
Only modes 0, 1 and 4 expose the USB Ethernet interfaces necessary for the ipheth driver.
Check the second byte of the control message where possible, and fall back to checking the first byte on older iOS versions.
Signed-off-by: Foster Snowhill forst@pen.gy Tested-by: Georgi Valkov gvalkov@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/ipheth.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/usb/ipheth.c b/drivers/net/usb/ipheth.c index 0774d753dd316..208336c871be5 100644 --- a/drivers/net/usb/ipheth.c +++ b/drivers/net/usb/ipheth.c @@ -253,13 +253,14 @@ static int ipheth_carrier_set(struct ipheth_device *dev) 0x02, /* index */ dev->ctrl_buf, IPHETH_CTRL_BUF_SIZE, IPHETH_CTRL_TIMEOUT); - if (retval < 0) { + if (retval <= 0) { dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n", __func__, retval); return retval; }
- if (dev->ctrl_buf[0] == IPHETH_CARRIER_ON) { + if ((retval == 1 && dev->ctrl_buf[0] == IPHETH_CARRIER_ON) || + (retval >= 2 && dev->ctrl_buf[1] == IPHETH_CARRIER_ON)) { netif_carrier_on(dev->net); if (dev->tx_urb->status != -EINPROGRESS) netif_wake_queue(dev->net);