Re: fixing mpii(4) for tls_maxphys, updated

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Sat, Jan 11, 2014 at 06:39:55AM +0100, Emmanuel Dreyfus wrote:
> 
> First, the request size of 512 in our driver is wrong. The controller
> expects 128 bytes requests, which the following layout:
> - 96 bytes of struct mpii_msg_scsi_io
> - 2x12 bytes of scatter-gather entry (SGE)
> - 8 unused bytes

At a guess, is this carried over from the mpi and perhaps even the mpt
drivers?  They have a very strange maximum transfer size restriction
based on fitting all SGE entries into a single request, 192KB IIRC.

> That does not fit at all with how the driver is written. There is a
> dmamap for requests, and mpii_load_xs() uses a struct mpii_ccb for a
> given transfer. That structure is asociated with a single request, while
> it should be able to be associated with up to 16. 
> 
> Ideas on how to refactor the code are welcome.

I'm sorry I've been so busy, but I will try to spend some time on this
next week -- I have at least found an mpii card I can probably borrow
from work. :-)

Thor