Coordinate based QoS escalation

摘要

Systems and methods for determining priorities of pixel fetch requests of separate requestors in a display control unit. The distance between the oldest pixel in an output buffer and the output equivalent coordinate of the oldest outstanding source pixel read request for each requestor in the display control unit is calculated. Then, a priority is assigned to each requestor based on this calculated distance. If a given requestor lags behind the other requestors based on a comparison of the distance between the oldest pixel and the output equivalent coordinate of the oldest outstanding source pixel read, then source pixel fetch requests for this given requestor are given a higher priority than source pixel fetch requests for the other requestors.

主权项

1. A method comprising:
identifying an oldest output pixel stored in a display pipeline for a first requestor; identifying an oldest outstanding pixel fetch request of the first requestor, wherein the oldest outstanding pixel fetch request is for a first source pixel; calculating an output equivalent coordinate of the first source pixel, wherein the output equivalent coordinate of the first source pixel is a coordinate of an earliest output pixel that cannot be generated without the first source pixel; calculating a first distance in output pixels between the oldest output pixel and the output equivalent coordinate of the first source pixel within a given output frame; determining a first quality of service (QoS) level based at least in part on the first distance; and assigning the first QoS level to the oldest outstanding pixel fetch request of the first requestor, wherein requests with the first QoS level are serviced with a higher priority than requests with a second QoS level.