On 11/23/2012 07:01 PM, Frank Schäfer wrote:
Hi, I've got a Hauppauge HVR-900 (65008/A1C0) today. First, the device showed up as USB device 7640:edc1 (even after several unplug - replug cycles), so I decided to add this VID:PID to the em28xx driver to see what happens. That worked fine, em2882/em2883, tuner xc2028/3028 etc. were detected properly. Later I noticed, that the device now shows up as 2040:6500, which is the expected ID for this device. Since then, the device maintains this ID. I also checked if Windows is involved, but it shows up with the same ID there. Does anyone have an idea what could have happened ??? I wonder if we should add this ID to the em28xx driver...
em28xx chip reads USB ID from the external eeprom using I2C just after it was powered. After USB ID is got it connects to the USB bus using that ID. If there is no external eeprom it uses chipset default USB ID, which is 0xeb1a as vendor ID and some other number defined for chip model as device ID. In that case those wrong IDs seems to be total garbage, which indicates there is some hardware problems when communicating towards eeprom.
That method is not only Empia USB interface chips but almost all chipset uses just similar method.
regard Antti -- http://palosaari.fi/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
