Re: [PATCH 06/14] net: ks8851: Remove ks8851_rdreg32()

On Tue, Mar 24, 2020 at 12:42:55AM +0100, Marek Vasut wrote:

The ks8851_rdreg32() is used only in one place, to read two registers
using a single read. To make it easier to support 16-bit accesses via
parallel bus later on, replace this single read with two 16-bit reads
from each of the registers and drop the ks8851_rdreg32() altogether.

This doubles the SPI transactions necessary to read the RX queue status,
which happens for each received packet, so I expect the performance
impact to be noticeable.  Can you keep the 32-bit variant for SPI
and instead just introduce a 32-bit read for the MLL chip which performs
two 16-bit reads internally?

Thanks,

Lukas