Subject: Re: sys/scsi bug: adaptor-level driver miphys routine not honoured by cluster_read()?
To: Jonathan Stone <email@example.com>
From: Chris G Demetriou <Chris_G_Demetriou@BALVENIE.PDL.CS.CMU.EDU>
Date: 09/18/1995 18:36:46
> I'm re-writing a TurboChannel ASC (53c94, like the "esp")
> driver using the machine-independent SCSI code in sys/scsi.
> I want to use a minphys routine in the SCSI sc_link.adapter
> switch to limit SCSI I/O requests to 8 Kbytes, since the
> current driver doesn't deal with larger requests than that
> directly, and fixing it is tricky.
> It seems like the adpater->scsi_minphys function does just
> what I want.
minphys() is only called when you're doing 'raw' operations on
block operations, such as those used by file systems, don't use it.
minphys()'s purpose is to limit the amount of RAM that will be locked
down for given raw transfer.