Hi Grant: * Grant Coady <grant_nospam at dodo.com.au> [2005-03-23 09:25:25 +1100]: > Hi All, > > Requesting information on two issues, taking a the lock for > read/modify/write i2c chip update cycles, and rate limiting > write access to i2c bus to prevent user-space DoS on the i2c > bus with continuous update requests. > > i2c locking: > > Thinking about the fan_div setting, it is a read/modify/write > (RMW) operation to a chip register, should we take action to > prevent another process accessing the chip on i2c during this > RMW action? Looks like Philip addressed this one. > preventing DoS, updating i2c bus chips > > Another query, we take care not to read chip too frequently, > what stops user-space DoS'ing the i2c bus with continuous > writes by constant update requests? Nothing prevents it, except that you need root to do those writes/updates. Considering all the other damage you can do as root... there's not much point in any further protection for the I2C bus. Regards, -- Mark M. Hoffman mhoffman at lightlink.com
