ARM imx.6 SATA speed regression

[Dan MacDonald]

Hi LKML

I recently got a SABRE Lite, iMX.6q based SBC. I bought this board
over the RPi3, for example, because I wanted SATA and open source
graphics drivers via etnaviv / armada.

Under Arch Linux ARM with Linux 4.9.0, hdparm said I was getting an
average of ~120 MB/s buffered disk read speed. After upgrading to
Linux 4.9.8 buffered read speed is just under 90 MB/s. That's a
notable hit! I both cases I was running the stock ALARM armv7h kernel
package.

Might any of you Linux ARM devs know what has changed since 4.9.0 that
could cause such a big decrease in SATA IO?

Thanks