Bug 79272

Summary: "ata" detects and enables UDMA66 or UDMA100 with 40 wire cable
Product: Base System Reporter: Murray Baker <murray_baker>
Component: i386Assignee: Remko Lodder <remko>
Status: Closed FIXED    
Severity: Affects Only Me    
Priority: Normal    
Version: Unspecified   
Hardware: Any   
OS: Any   

Description Murray Baker 2005-03-27 06:00:09 UTC 
      "ata" driver detects too high an xDMAx speed, several hw
combinations, 5.3-RELEASE. Incorrect cable identification?

1/ PCchips (SiS) P///-800 mobo, Pioneer DVD117, *40* wire cable, the
dvd is configured for UDMA66 (partially works, unreliable).

2/ Various socket 7 mobo, PCI card with CMD0649 chip, Maxtor D740X-6L
HDD (probably others also), *40* wire cable, hdd is configured for
UDMA100 (doesn't work).

(I have probably seen this on other hw combinations also.)

"atacontrol" can be used to reconfigure a dvd after booting. The worse
problem is hdd, trying to boot install media and do an install.

How-To-Repeat:       Same hw?
Comment 1 Remko Lodder freebsd_committer freebsd_triage 2005-12-26 15:16:11 UTC 
State Changed
From-To: open->feedback

Getting feedback from the submitter. Requested some more 
which might clarify the issue mentioned. 

Currently i am thinking that one of the hardware devices 
might tell the controller that is capable of running at 
UDMA100 (or UDMA66 for that matter) while it might not 
be able to do so. 

Suggested to test FreeBSD 6.0 so that we can see whether 
this problem still persists.
Comment 2 Remko Lodder freebsd_committer freebsd_triage 2005-12-26 15:16:11 UTC 
Responsible Changed
From-To: freebsd-i386->remko

Assign the PR to me, so that i can recieve feedback 
and get reminders :)
Comment 3 Remko Lodder freebsd_committer freebsd_triage 2006-06-13 19:13:01 UTC 
State Changed
From-To: feedback->closed

Latest information from the submitter: 

I have learned more about these problems. Many early xDMAx hw 
controllers are defective. The solution is simple. 
* All ATA controllers capable max UDMA33 should be restricted 
to PIO4 mode by default. A configuration option is then required 
to allow higher speed modes.