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