On Tue, 15 Aug 2017 18:02:57 -0400
Ken Goldman [off-list ref] wrote:

On 8/13/2017 7:53 PM, msuchanek wrote:

quoted

About 500 out of 700 mainboards sold today has a PS/2 port which is
probably due to prevalence of legacy devices and usbhid limitations.

Similarily many boards have serial and parallel hardware ports.

In all diagrams detailed enough to show these ports I have seen them
attached to the LPC bus.  

Do these boards have a TPM?  Remember that the TPM requires special
LPC bus cycles.

Out of nearly 700 boards over 500 have PS/2 connector and over 400
have TPM slot (which is subset of the PS/2 enabled boards). Some more
possibly have on-board TPM chip.

Even if so, the TPM LPC bus wait states are less than a usec.  My 
thought is that  it's unlikely that any device (serial port, mouse, 
keyboard, printer) will be adversely affected.

Yes, in theory this is negligible. So unless there is a possibility
these wait states chain or the device otherwise takes over the bus for
extended period of time this should be fine.

Thanks

Michal
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