Re: [PATCH 01/23] devicetree: bindings: hisi_sas: add v2 HW bindings

From: John Garry
Date: Fri Jan 08 2016 - 10:35:54 EST

+Optional main node properties:
+ - am-max-trans : limit controller for am max transmissions

Is this a boolean? Number?

This is a boolean. It is for dealing with a quirk in the chipset: an
instance of the controller in the hip06 chipset requires registers
set with a different init value.

Ok. I think the property at needs a better description for that.

It's not clear to me how "limit controller for am max transmissions"
maps to writing a specific value to some registers, but I don't know
much about SAS.

Is this some well-known thing, or values specific to hip06?


This is a specific issue for hip06 chipset. There is a bug in the HW on hip06 where controller #1 has to set to 2 registers to non-default values to limit "am-max-transmissions". This would not be a common SAS/SCSI controller property and is specific to our HW.