On Mon, Jan 31, 2022 at 04:18:08PM PST, Zev Weiss wrote:
Hello, This series adds support for a new pca9541 device-tree property ("release-delay-us"), which delays releasing ownership of the bus after a transaction for a configurable duration, anticipating that another transaction may follow shortly. By avoiding a release/reacquisition between transactions, this can provide a substantial performance improvement for back-to-back operations -- on a Delta AHE-50DC (ASPEED AST1250) system running OpenBMC with dozens of LM25066 PMICs on PCA9541-arbitrated busses, a setting of 10000 (10 ms) reduces the median latency the psusensor daemon's hwmon sysfs file reads from 2.28 ms to 0.99 ms (a 57% improvement).
Ping...Guenter, any thoughts on this? Thanks, Zev