mpt driver patch

[Jan_Rybensky at env.cz]

Hi All, 

as well as the others I've encoutered serious performace problems with IM 
volumes on LSI 1030 controller. It's because the mpt driver is unable to 
detect hidden disks of the IM volumes and initialize them. That disks 
operates at default SCSI speed and slows the whole volume.
This patch is far from perfect (not performs full DV), but it solves the 
performance issues. It seems to be stable, but it's tested only on IBM 
version of controller (on-board controllers of xSeries 335, 345). 

There is other issue I'm unable to solve: although all discs operating at 
proper speeds, the resync of mirrored disks is still very slow. The 
controller probably needs additional initializations, but I'm unable to 
trace them in linux driver. Can anybody help? Any suggestions are 
welcomed. 

Here is diff against 4.9-REL mpt sources (it works well on 4.10-REL too) 
and a tarball of the whole mpt directory from /sys/dev with patched driver 
sources is here: http://mpt-freebsd.env.cz.
 
Many thanks for any feedback.

        Jan Rybensky


-------------------------------------------------------------------------------------
Jan Rybensky
Senior Network Administrator
tel: ++420 267 122 547
fax: ++420 267 126 547
GSM: ++420 605 292 601
email: jry at env.cz
snail:  Ministry of Environment of the Czech Republic
        Informatics department
        Vrsovicka 65
        100 10 Praha 10