CRITICALITY

Low

DESCRIPTION

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.

WORKAROUND

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.

REVISIONS IMPACTED

SR 2.0, 1.1, 1.0

TDA2x: 2.0, 1.1, 1.0

DRA75x, DRA74x: 2.0, 1.1, 1.0

AM572x: 2.0, 1.1