[PATCH v2 0/2] ic2: mux: pca9541: add delayed-release support

[Zev Weiss]

On Mon, Feb 28, 2022 at 05:57:27AM PST, Guenter Roeck wrote:
>On 2/28/22 00:43, Zev Weiss wrote:
>>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?
>>
>
>It sounds reasonable to me, but I don't have access to hardware anymore
>to test it, so I have no means to confirm that it actually works.
>

Ack, thanks.  In that case, what's the path forward on getting changes 
to this driver merged?  I see sign-offs from Wolfram and Peter on the 
last few commits that touched it -- any input from the i2c/i2c-mux 
maintainers?


Zev