Re: [PATCH RFC 3/5] Add KSZ8795 switch driver

[Andrew Lunn]

> My concern is if a task is already running with SPI access to a lot
> of registers like reading the 32 MIB counters in every port of the
> switch, another register access has to wait until they are finished.

Why does it have to wait? Looking at the code in
ksz_get_ethtool_stats(), you don't take any mutex which will prevent
others from using the SPI bus. All there is is a mutex which prevents
two sets of ksz_get_ethtool_stats() at the same time.

So a PTP read could happen in parallel, and will not be blocked by MIB
reads. They should get interleaved access to the SPI bus.

       Andrew