Alan,

> Fix the problem by adding the I2C_AQ_NO_ZERO_LEN_READ adapter quirk
> flag to all the USB I2C adapter devices managed by dvb-usb-i2c.c,
> following Wolfram Sang's suggestion.  This tells the I2C core not to
> allow length-0 read messages.

Thank you again for fixing this issue. There are some USB-I2C bridges in
drivers/i2c/busses which also do not prevent zero len reads. Would it
make sense to put a protection into the I2C core? Can we reliably detect
that an adapter sits on a USB (maybe via the parent device), so that we
can then check if I2C_AQ_NO_ZERO_LEN_READ is set, and take action if
not?

Appreciating your input,

   Wolfram