And now for a tough
one to solve...
SUMMARY:
What happens to the soft settings of a drive during a Async loss of signal
?
(such as UDMA mode, IDP values, Multi settings or any other setfeat soft
setting)
SUGGESTION:
Drives need to know
the difference between a Async loss of signal and a commanded
COMRESET.
If it is a
Async loss of signal, they need to maintain the "soft settings", if its a
commanded COMRESET, they need
to reset all the
settings and expect the OS to reprogram them
BACKGROUND:
On SATA Comreset is
equated to HRESET on PATA. Also Async loss of signal on SATA is equated to
COMRESET....
HOWEVER, there is a
problem (ok only one -:) with this assumption.
On PATA HRESET
happens VERY view times (at boot, commanded reboot and coming out of S3 and
S4). Each
of these times the
OS / BIOS is VERY aware that this is happening.
HOWEVER, on SATA
Async loss of signal is NOT commanded and the OS is NOT very aware and has NO
was of knowing if it is not VERY SATA aware (aka the OS would have to poll the
SATA SERROR / SSTATUS non-standard location registers).
Thus the OS does not
know to comedown and reprogram the drive with the right UDMA mode, multi setting
for read multiple,
IDP values,
etc).
CURRENT
SITUATION:
Several SATA drives
on the market today will totally lock up and a SRST will NOT get them out
of this condition.
Example 1: On
a Async loss of signal, Several drives will reset the PATA portion (thus loose
the soft setting of DMA mode
and revert back to
multiword DMA), the SATA to PATA conversion portion is fixed in UDMA
mode... BINGO... LOCK up
Example 2: BIOS / OS
setup a multi setting of 16 for a read / write multiple. Then a ASYNC loss
of signal, multi reverts
back to 1 or
something other than 16 on the drive. OS does a write multi... BINGO Lock
up
.... And the list
goes on.
All soft settings
need to be addressed.
Jeff
Jeff
Wolford
Email: [EMAIL PROTECTED]
Senior Architect
Storage Interface and Tools - Business PC Products Group
Voice: (281) 514-9465, Pager: (800) 973-5739
Hewlett-Packard Corporation
Senior Architect
Storage Interface and Tools - Business PC Products Group
Voice: (281) 514-9465, Pager: (800) 973-5739
Hewlett-Packard Corporation
