i2c: robotfuzz-osif: disable zero-length read messages

This driver passes the length of an i2c_msg directly to
usb_control_msg(). If the message is now a read and of length 0, it
violates the USB protocol and a warning will be printed. Enable the
I2C_AQ_NO_ZERO_LEN_READ quirk for this adapter thus forbidding 0-length
read messages altogether.

Fixes: 83e53a8 ("i2c: Add bus driver for for OSIF USB i2c device.")
Signed-off-by: Wolfram Sang <[email protected]>
Cc: <[email protected]> # v3.14+
Signed-off-by: Andi Shyti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Wolfram Sang

drivers/i2c/busses/i2c-robotfuzz-osif.c

@@ -111,6 +111,11 @@ static u32 osif_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 }
 
+/* prevent invalid 0-length usb_control_msg */
+static const struct i2c_adapter_quirks osif_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN_READ,
+};
+
 static const struct i2c_algorithm osif_algorithm = {
 	.xfer = osif_xfer,
 	.functionality = osif_func,
@@ -143,6 +148,7 @@ static int osif_probe(struct usb_interface *interface,
 
 	priv->adapter.owner = THIS_MODULE;
 	priv->adapter.class = I2C_CLASS_HWMON;
+	priv->adapter.quirks = &osif_quirks;
 	priv->adapter.algo = &osif_algorithm;
 	priv->adapter.algo_data = priv;
 	snprintf(priv->adapter.name, sizeof(priv->adapter.name),