Bug 171282 - Only FAST-SCSI when previous kernels delivered U-SCSI for AIC7880
Only FAST-SCSI when previous kernels delivered U-SCSI for AIC7880
Status: CLOSED WONTFIX
Product: Fedora
Classification: Fedora
Component: kernel (Show other bugs)
14
i686 Linux
medium Severity medium
: ---
: ---
Assigned To: Tom Coughlan
Brian Brock
bzcl34nup
: Reopened
Depends On:
Blocks:
  Show dependency treegraph
 
Reported: 2005-10-20 08:15 EDT by Joachim Frieben
Modified: 2012-08-16 17:38 EDT (History)
3 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Environment:
Last Closed: 2012-08-16 17:38:20 EDT
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
CRM:
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Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:


Attachments (Terms of Use)
SCSI portion of "dmesg" for 2.6.12-1.1447_FC4smp kernel (1.96 KB, text/plain)
2005-10-24 02:53 EDT, Joachim Frieben
no flags Details
SCSI portion of "dmesg" for 2.6.13-1.1532_FC4smp kernel (2.03 KB, text/plain)
2005-10-24 02:54 EDT, Joachim Frieben
no flags Details
SCSI portion of "dmesg" for 2.6.14-1.1740_FC5smp kernel (991 bytes, text/plain)
2005-12-08 09:24 EST, Joachim Frieben
no flags Details
SCSI portion of "dmesg" for 2.6.17-1.2532.fc6 SMP kernel (1.14 KB, text/plain)
2006-08-10 05:28 EDT, Joachim Frieben
no flags Details

  None (edit)
Description Joachim Frieben 2005-10-20 08:15:49 EDT
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051018 Epiphany/1.8.2

Description of problem:
After upgrading the SMP kernel on my PR440FX box, the SCSI
subsystem switched from U-SCSI to FAST-SCSI mode. There are
three devices connected to the on-board AHA-2940UW device.
This never happened before up to revision 2.6.12-1.1447_FC4.
The relevant section of the "dmesg" log message looks quite
different now. Some major changes related to the SCSI system
seem to have happened between kernel version 2.6.12 and 2.6.13.

Version-Release number of selected component (if applicable):
kernel-smp-2.6.13-1.1526_FC4

How reproducible:
Always

Steps to Reproduce:
1. Boot with 2.6.13-1.1526_FC4 SMP kernel.
2. Check the output of "dmesg".
  

Actual Results:  Transfer mode should be U-SCSI (20 MB/s) as before.

Expected Results:  Transfer mode is FAST-SCSI (10 MB/s).

Additional info:

The hard disk transfer drops from about 28 MB/s to a
disappointing 18 MB/s whereby the latter is obvious
having in mind that the disk operates in "wide" mode.
The upper limit hence is 20 MB/s.
Booting the 2.6.12-1.1447_FC4 kernel restores the
U-SCSI mode. Consequently, it is not a matter of BIOS
settings etc.
Comment 1 Joachim Frieben 2005-10-20 08:36:02 EDT
Ok, the SCSI-subsystem is indeed identical (v6.2.36). Looking at the
content of "/var/log/dmesg" though reveals that for the latest kernel,
*asynchronous* transfer mode is adopted which explains the limits of
10 MB/s for 8-Bit and 20 MB/s for 16-Bit devices. The attached hard
disk is a QUANTUM Atlas 10k III drive.
Comment 2 Joachim Frieben 2005-10-24 02:53:49 EDT
Created attachment 120298 [details]
SCSI portion of "dmesg" for 2.6.12-1.1447_FC4smp kernel
Comment 3 Joachim Frieben 2005-10-24 02:54:36 EDT
Created attachment 120299 [details]
SCSI portion of "dmesg" for 2.6.13-1.1532_FC4smp kernel
Comment 4 Joachim Frieben 2005-10-24 08:45:23 EDT
I verified my observation by installing an AHA-2940U2W PCI card.
The "dmesg" log looks pretty much like the previous one for the
on-board AIC7880 chip.
Even the "asynchronous" message is issued. However, transfer mode
now is FAST-40 SCSI compared to FAST-10 mode for the AIC7880 chip.
This gives a factor of 4 where it should only be 2. Looks like a
problem specifically related to to the AIC7880.
In both cases, I had disconnected any drive except for the QUANTUM
Atlas 10k III.
Comment 5 Dave Jones 2005-11-10 15:27:18 EST
2.6.14-1.1637_FC4 has been released as an update for FC4.
Please retest with this update, as a large amount of code has been changed in
this release, which may have fixed your problem.

Thank you.
Comment 6 Joachim Frieben 2005-12-08 09:21:18 EST
Still not fixed in 2.6.14-1.1740_FC5smp. As before, I disconnected
any other device but the U160 hard disk before booting.
The kernel continues to negotiate FAST-10 WIDE mode which limits
data transfers to 20 MB/s. In practice, I obtain about 18 MB/s.
Comment 7 Joachim Frieben 2005-12-08 09:24:52 EST
Created attachment 122030 [details]
SCSI portion of "dmesg" for 2.6.14-1.1740_FC5smp kernel
Comment 8 Joachim Frieben 2006-01-29 06:18:18 EST
Still not fixed in 2.6.15-1.1881_FC5smp.
Comment 9 Dave Jones 2006-02-03 01:14:49 EST
This is a mass-update to all currently open kernel bugs.

A new kernel update has been released (Version: 2.6.15-1.1830_FC4)
based upon a new upstream kernel release.

Please retest against this new kernel, as a large number of patches
go into each upstream release, possibly including changes that
may address this problem.

This bug has been placed in NEEDINFO_REPORTER state.
Due to the large volume of inactive bugs in bugzilla, if this bug is
still in this state in two weeks time, it will be closed.

Should this bug still be relevant after this period, the reporter
can reopen the bug at any time. Any other users on the Cc: list
of this bug can request that the bug be reopened by adding a
comment to the bug.

If this bug is a problem preventing you from installing the
release this version is filed against, please see bug 169613.

Thank you.
Comment 10 Joachim Frieben 2006-02-03 06:14:35 EST
I had already moved to FC5-rawhide some time ago where the problem is
also present, e.g. for kernel version 2.6.15-1.1885_FC5smp.
Comment 11 Joachim Frieben 2006-02-11 09:21:03 EST
Still not fixed in 2.6.15-1.1831_FC4smp either.
Comment 12 Joachim Frieben 2006-02-22 04:46:29 EST
Still not fixed in 2.6.15-1.1969_FC5smp.
Comment 13 Joachim Frieben 2006-02-26 06:52:23 EST
In the meantime, another user has posted a bug report upstream for this
issue, see: 

  http://bugzilla.kernel.org/show_bug.cgi?id=5808
Comment 14 Joachim Frieben 2006-03-09 04:27:26 EST
Still not fixed in 2.6.15-1.2032_FC5smp.
Comment 15 Joachim Frieben 2006-04-22 09:47:43 EDT
Still present in both 2.6.15-1.2096_FC5smp and 2.6.16-1.2147_FC6. Very
annoying!
Comment 16 Joachim Frieben 2006-04-22 09:52:17 EDT
The first is one is 2.6.16-1.2096_FC5smp, sorry.
                        ^^
Comment 17 Joachim Frieben 2006-08-10 05:28:30 EDT
Created attachment 133919 [details]
SCSI portion of "dmesg" for 2.6.17-1.2532.fc6 SMP kernel
Comment 18 Joachim Frieben 2006-08-10 05:34:01 EDT
Kernel 2.6.17-1.2532.fc6 still negotiates "FAST-10 WIDE SCSI" mode
when it should be "FAST-20 WIDE SCSI".
Comment 19 Joachim Frieben 2006-12-18 04:45:01 EST
Still broken in kernel "2.6.19-1.2877.fc7".
Comment 20 Joachim Frieben 2007-06-10 05:28:38 EDT
Still broken in kernel "2.6.21-1.3194.fc7"
Comment 22 Joachim Frieben 2007-07-25 11:12:30 EDT
Still broken in kernel "2.6.23-0.45.rc0.git16.fc8".
Comment 23 Joachim Frieben 2007-07-30 05:15:24 EDT
There is some progress on this issue since by executing

  echo 50 > /sys/class/spi_transport/target0:0:0/min_period
  echo  1 > /sys/class/spi_transport/target0:0:0/revalidate

the SCSI controller can be switched to ULTRA mode as reported by dmesg:

  target0:0:0: Beginning Domain Validation
  target0:0:0: asynchronous
  target0:0:0: wide asynchronous
  target0:0:0: FAST-20 WIDE SCSI 40.0 MB/s ST (50 ns, offset 8)
  target0:0:0: Domain Validation skipping write tests
  target0:0:0: Ending Domain Validation

Transfer mode is reported as asynchronous but this seems to be ok.
However, for development kernel version 2.6.23-0.49.rc1.git3.fc8,
the improvement even in single user mode is small.
One manages to achieve a transfer rate of about 20 MB/s instead
of 18 MB/s. Only after booting the latest F7 update kernel
2.6.22.1-33.fc7, the transfer rate achieved a value of about 28 MB/s
which seems reasonable for a U160 hard disk connected to a 2940UW
controller in SE mode. Using a Ubuntu live CD where the hard disk is
not at all used by the OS itself, I even obtained a rate of about
32 MB/s. It seems that the debug options of Fedora development kernels
have a huge impact on SCSI performance which actually misled me for
a while.
To summarize: SCSI operations is correct after switching the mode to
U-SCSI by hand. What thus merely needs to be fixed is the wrong
negociation of FAST-10 instead of FAST-20 mode.
Comment 24 Bug Zapper 2008-04-03 12:33:12 EDT
Based on the date this bug was created, it appears to have been reported
against rawhide during the development of a Fedora release that is no
longer maintained. In order to refocus our efforts as a project we are
flagging all of the open bugs for releases which are no longer
maintained. If this bug remains in NEEDINFO thirty (30) days from now,
we will automatically close it.

If you can reproduce this bug in a maintained Fedora version (7, 8, or
rawhide), please change this bug to the respective version and change
the status to ASSIGNED. (If you're unable to change the bug's version
or status, add a comment to the bug and someone will change it for you.)

Thanks for your help, and we apologize again that we haven't handled
these issues to this point.

The process we're following is outlined here:
http://fedoraproject.org/wiki/BugZappers/F9CleanUp

We will be following the process here:
http://fedoraproject.org/wiki/BugZappers/HouseKeeping to ensure this
doesn't happen again.
Comment 25 Bug Zapper 2008-05-06 20:15:28 EDT
This bug has been in NEEDINFO for more than 30 days since feedback was
first requested. As a result we are closing it.

If you can reproduce this bug in the future against a maintained Fedora
version please feel free to reopen it against that version.

The process we're following is outlined here:
http://fedoraproject.org/wiki/BugZappers/F9CleanUp
Comment 26 Joachim Frieben 2008-08-06 16:53:51 EDT
Comment #23 still fully applies to current F9 w/updates plus
kernel-2.6.26.1-9.fc9.i686. The issue thus persists.
Comment 27 Bug Zapper 2009-06-09 18:03:55 EDT
This message is a reminder that Fedora 9 is nearing its end of life.
Approximately 30 (thirty) days from now Fedora will stop maintaining
and issuing updates for Fedora 9.  It is Fedora's policy to close all
bug reports from releases that are no longer maintained.  At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '9'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version prior to Fedora 9's end of life.

Bug Reporter: Thank you for reporting this issue and we are sorry that 
we may not be able to fix it before Fedora 9 is end of life.  If you 
would still like to see this bug fixed and are able to reproduce it 
against a later version of Fedora please change the 'version' of this 
bug to the applicable version.  If you are unable to change the version, 
please add a comment here and someone will do it for you.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events.  Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

The process we are following is described here: 
http://fedoraproject.org/wiki/BugZappers/HouseKeeping
Comment 28 Bug Zapper 2010-04-27 07:37:46 EDT
This message is a reminder that Fedora 11 is nearing its end of life.
Approximately 30 (thirty) days from now Fedora will stop maintaining
and issuing updates for Fedora 11.  It is Fedora's policy to close all
bug reports from releases that are no longer maintained.  At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '11'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version prior to Fedora 11's end of life.

Bug Reporter: Thank you for reporting this issue and we are sorry that 
we may not be able to fix it before Fedora 11 is end of life.  If you 
would still like to see this bug fixed and are able to reproduce it 
against a later version of Fedora please change the 'version' of this 
bug to the applicable version.  If you are unable to change the version, 
please add a comment here and someone will do it for you.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events.  Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

The process we are following is described here: 
http://fedoraproject.org/wiki/BugZappers/HouseKeeping
Comment 29 Bug Zapper 2010-06-28 06:20:56 EDT
Fedora 11 changed to end-of-life (EOL) status on 2010-06-25. Fedora 11 is 
no longer maintained, which means that it will not receive any further 
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of 
Fedora please feel free to reopen this bug against that version.

Thank you for reporting this bug and we are sorry it could not be fixed.
Comment 30 Joachim Frieben 2011-03-03 14:08:39 EST
For current F13 including kernel-2.6.34.7-66.fc13.i686, min_period is still erroneously set to 100 ns instead of 50 ns. As measured by gnome-disk-utility, forcing a value of 50 ns for min_period following the procedure outlined in comment 23, the average read rate jumps from 18 MB/s to 34 MB/s.
Comment 31 Bug Zapper 2011-06-02 14:44:44 EDT
This message is a reminder that Fedora 13 is nearing its end of life.
Approximately 30 (thirty) days from now Fedora will stop maintaining
and issuing updates for Fedora 13.  It is Fedora's policy to close all
bug reports from releases that are no longer maintained.  At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '13'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version prior to Fedora 13's end of life.

Bug Reporter: Thank you for reporting this issue and we are sorry that 
we may not be able to fix it before Fedora 13 is end of life.  If you 
would still like to see this bug fixed and are able to reproduce it 
against a later version of Fedora please change the 'version' of this 
bug to the applicable version.  If you are unable to change the version, 
please add a comment here and someone will do it for you.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events.  Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

The process we are following is described here: 
http://fedoraproject.org/wiki/BugZappers/HouseKeeping
Comment 32 Joachim Frieben 2011-06-05 03:55:22 EDT
Issue still applies to F14 and the latest kernel-2.6.35.13-92.fc14.
Comment 33 Fedora End Of Life 2012-08-16 17:38:23 EDT
This message is a notice that Fedora 14 is now at end of life. Fedora 
has stopped maintaining and issuing updates for Fedora 14. It is 
Fedora's policy to close all bug reports from releases that are no 
longer maintained.  At this time, all open bugs with a Fedora 'version'
of '14' have been closed as WONTFIX.

(Please note: Our normal process is to give advanced warning of this 
occurring, but we forgot to do that. A thousand apologies.)

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, feel free to reopen 
this bug and simply change the 'version' to a later Fedora version.

Bug Reporter: Thank you for reporting this issue and we are sorry that 
we were unable to fix it before Fedora 14 reached end of life. If you 
would still like to see this bug fixed and are able to reproduce it 
against a later version of Fedora, you are encouraged to click on 
"Clone This Bug" (top right of this page) and open it against that 
version of Fedora.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events.  Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

The process we are following is described here: 
http://fedoraproject.org/wiki/BugZappers/HouseKeeping

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