| Message ID | 20250522064349.3823-2-wsa+renesas@sang-engineering.com |
|---|---|
| State | New |
| Headers | show |
| Series | i2c: tiny-usb: disable zero-length read messages | expand |
> > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > > > > Fixes: e8c76eed2ecd ("i2c: New i2c-tiny-usb bus driver") > > I will queue these up for next week. There are a few more fixes > that I deliberately left out of this week's pull request to give > them time to be properly reviewed and tested. Sure thing, this problem has been around for years. It can wait a little more and will go to stable anyhow.
diff --git a/drivers/i2c/busses/i2c-tiny-usb.c b/drivers/i2c/busses/i2c-tiny-usb.c index 0f2ed181b266..0cc7c0a816fc 100644 --- a/drivers/i2c/busses/i2c-tiny-usb.c +++ b/drivers/i2c/busses/i2c-tiny-usb.c @@ -138,6 +138,11 @@ static u32 usb_func(struct i2c_adapter *adapter) return ret; } +/* prevent invalid 0-length usb_control_msg */ +static const struct i2c_adapter_quirks usb_quirks = { + .flags = I2C_AQ_NO_ZERO_LEN_READ, +}; + /* This is the actual algorithm we define */ static const struct i2c_algorithm usb_algorithm = { .xfer = usb_xfer, @@ -246,6 +251,7 @@ static int i2c_tiny_usb_probe(struct usb_interface *interface, /* setup i2c adapter description */ dev->adapter.owner = THIS_MODULE; dev->adapter.class = I2C_CLASS_HWMON; + dev->adapter.quirks = &usb_quirks; dev->adapter.algo = &usb_algorithm; dev->adapter.algo_data = dev; snprintf(dev->adapter.name, sizeof(dev->adapter.name),
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. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- drivers/i2c/busses/i2c-tiny-usb.c | 6 ++++++ 1 file changed, 6 insertions(+)