> I tried to run i2cdump on my Matrox Mystique, first with timeout=100, > second with timeout=50. It took 8s for each address scanned in the > first case, 4s for each address scanned in the second case. This shows > that the timeout is the value that makes it slow, but this also raise > another problem. I would have expected the average scan time to be > exactly the timeout value. And it is eight times higher.I checked the > i2cdump code and it only calls i2c_smbus_read_byte_data() once for > each address. Hm. I meant i2cdetect of course. So the function that is called is i2c_smbus_write_quick(), not i2c_smbus_read_byte_data(). BTW there is also an ioctl() call, which I am not familiar with. Could it also cause the slowdown too? -- Jean Delvare http://www.ensicaen.ismra.fr/~delvare/
