SPRZ426F November 2014 – September 2024 DRA710 , DRA712 , DRA714 , DRA716 , DRA718 , DRA722 , DRA724 , DRA725 , DRA726
USB xHCI Port Disable Feature Does Not Work
Low
USB software would typically disable the port if the attached device is behaving incorrectly or has become unresponsive. Due to the bug if the port is disabled using the PED bit in the PORTSC register, it subsequently fails to detect any detach/attach events. In other words, if the attached device were to be disconnected after it has been disabled using PED bit, the USB controller will be unable to detect and report it. This issue only applies to HighSpeed mode.
Option 1: If possible, use of Port Disable should be completely avoided. Since its use is only in error scenarios for eg. unresponsive devices, this is feasible.
Option 2: Instead of disabling the port, power off the port using PP and then power it back on. Now the port can detect attach/detach events again. To ensure that same scenario does not occur over and over, the erroneous device must be removed before attempting to recognize and enumerate a device again.
DRA72x SR 2.0, 1.0
DRA71x SR 2.1, 2.0
DRA79x: 2.1, 2.0
TDA2Ex (23mm): 2.0, 1.0
TDA2Ex (17mm): 2.1, 2.0
AM571x: 2.1, 2.0, 1.0
AM570x: 2.1, 2.0
DRA72x: 2.0, 1.0
DRA71x: 2.1, 2.0