Baseboard Management Controller HID Buffer Overflow Handling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Information handling systems face challenges in delivering key events to a host during high event rates due to overflow in the human interface device (HID) descriptor buffer, leading to potential loss or sluggish access.
Innovation Solution
A baseboard management controller manages the HID descriptor buffer by storing key events in a memory segment when full, sending an error code, clearing the buffer, and re-populating it with stored events, ensuring continuous key event delivery without loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the HID descriptor buffer is used to store key events during high event rates, then key event storage capacity is limited, but key event loss occurs when the buffer overflows
Solution Approach 1:
The patent divides the storage system into two segments: the HID descriptor buffer for immediate key event storage and an alternative buffer for overflow storage. This segmentation allows the system to maintain reliable key event delivery during high event rates by providing an additional storage location when the primary buffer is full, preventing key event loss while maintaining limited primary buffer capacity.
2Quantity of substance
If the HID descriptor buffer size is increased to prevent overflow, then key event storage capacity increases, but system responsiveness decreases due to buffer management overhead
Solution Approach 1:
The patent implements preliminary action by checking buffer status before storing key events and proactively transferring events from the alternative buffer to the HID descriptor buffer when space becomes available. This prevents overflow before it occurs and maintains system responsiveness by avoiding the need to handle overflow conditions, while still providing increased effective storage capacity through the alternative buffer.
3Reliability
If key events are stored in memory segment during buffer overflow, then key event loss is prevented, but device complexity increases
Solution Approach 1:
The patent uses feedback mechanisms where the baseboard management controller continuously monitors the HID descriptor buffer status and automatically triggers transfers from the alternative buffer when the primary buffer has available space. This feedback-driven approach maintains reliable key event delivery through structured buffer management while reducing perceived complexity by automating the buffer management process rather than requiring manual intervention or complex algorithms.
Data Source
AI summary
A baseboard management controller in an information handling system receives a human interface device input and converts the human interface device input into a human interface device scan code for storage at a human interface device descriptor buffer. The baseboard management controller determines whether or not the human interface device descriptor buffer is full and copying, when the human interface device descriptor buffer is full, the human interface scan codes in the human interface device descriptor buffer to a memory segment and sending an error code to a host system. The baseboard management controller also clears the human interface device descriptor buffer and re-populates the human interface device descriptor buffer with the human interface device scan code and the human interface device scan codes from the memory segment.