Hi, We have one USB 2.0 Controller on an ARM SoC, with internal PHY confirming to UTMI. The PHY would detect unexpected disconnect (amplitude of the differential envelop still < 625 mV) and assert the HostDisconnect signal to the Controller to indicate a disconnection event. When the HostDisconnect signal is asserted, the Controller will first do some internal clean work before it update CCS and CSC in PORTSCx and reports a Port Change Detect interrupt. We want to improve the situation by masking the HostDisconnect signal from PHY (take the cost into consideration), but it will cause no CCS and CSC update in PORTSCx, and no PCD interrupt. Thus the true disconnection only can be determined by an XactErr. Once the driver determine that it's a true disconnect, the HostDisconnect signal can be unmasked and the Controller will detect this disconnect. We are worried about the workaroud, since there may be many corner cases we have not taken into consideration, such as the race condition on connect and disconnect. So have you encountered this situation before? Or is there any suggestion on this workaround?
Thanks! Regards Rong -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
